{"title":"Power Tubes","description":"","products":[{"product_id":"el84-6bq5-sylvania-for-baldwin-gray-plates-matched-tubes-made-in-usa-56","title":"EL84 6BQ5 Baldwin\/SYLVANIA Matched Quad Gray Plates Halo Getter Tubes Made in USA '55","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cspan\u003e\u003cstrong\u003eEL84 ( 6BQ5 ) Baldwin\/SYLVANIA Matched Quad Gray Plates Halo Getter Tubes Made in USA '55\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp data-end=\"1197\" data-start=\"454\"\u003eThis matched quartet of \u003cstrong data-end=\"519\" data-start=\"508\"\u003eBaldwin\u003c\/strong\u003e branded \u003cstrong data-end=\"497\" data-start=\"482\"\u003eEL84 (6BQ5)\u003c\/strong\u003e tubes produced by \u003cstrong data-end=\"559\" data-start=\"534\"\u003eSylvania USA in 1955\u003c\/strong\u003e represents one of the finest examples of post-war American production.\u003cbr data-end=\"647\" data-start=\"644\"\u003eThe construction with \u003cstrong data-end=\"681\" data-start=\"666\"\u003egray plates\u003c\/strong\u003e , \u003cstrong data-end=\"717\" data-start=\"683\"\u003ering getter (Halo Getter)\u003c\/strong\u003e and compact frame with black base offers an exemplary combination of \u003cstrong data-end=\"844\" data-start=\"789\"\u003erobustness, tonal balance and dynamic precision\u003c\/strong\u003e . \u003cbr data-end=\"848\" data-start=\"845\"\u003eBaldwin\/Sylvania tubes were selected for use in professional audio equipment and high-end electric organs, where \u003cstrong data-end=\"1059\" data-start=\"1005\"\u003elow microphonics and absolute electrical stability\u003c\/strong\u003e were required.\u003cbr\u003e\u003c\/p\u003e\n\u003cp data-end=\"1232\" data-start=\"1204\"\u003e\u003cstrong data-end=\"1232\" data-start=\"1206\"\u003eSound Characteristics\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli data-end=\"1363\" data-start=\"1236\"\u003e\u003cstrong data-end=\"1246\" data-start=\"1236\"\u003eBass:\u003c\/strong\u003e solid and controlled, with excellent anchoring in the mid-low register; no tendency towards emphasis or resonance.\u003c\/li\u003e\n\u003cli data-end=\"1470\" data-start=\"1366\"\u003e\u003cstrong data-end=\"1375\" data-start=\"1366\"\u003eMids:\u003c\/strong\u003e Authentic and full-bodied, with natural timbre and realistic presence of vocals and acoustic instruments.\u003c\/li\u003e\n\u003cli data-end=\"1573\" data-start=\"1473\"\u003e\u003cstrong data-end=\"1482\" data-start=\"1473\"\u003eHighs:\u003c\/strong\u003e extended but never aggressive, with a refined brilliance typical of 1950s Sylvanias.\u003c\/li\u003e\n\u003cli data-end=\"1686\" data-start=\"1576\"\u003e\u003cstrong data-end=\"1589\" data-start=\"1576\"\u003eDynamics:\u003c\/strong\u003e responsive and well-proportioned; excellent microcontrast that enhances detail without being harsh.\u003c\/li\u003e\n\u003cli data-end=\"1829\" data-start=\"1689\"\u003e\u003cstrong data-end=\"1704\" data-start=\"1689\"\u003eSoundstage:\u003c\/strong\u003e Wide and deep, with stable and coherent imaging; it delivers a sense of three-dimensional realism that is rare in modern EL84s.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-end=\"1869\" data-start=\"1836\"\u003e🎧 \u003cstrong data-end=\"1869\" data-start=\"1839\"\u003eUse in Hi-Fi Amplifiers\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-end=\"2279\" data-start=\"1871\"\u003eIdeal for high-end \u003cstrong data-end=\"1909\" data-start=\"1896\"\u003epush-pull\u003c\/strong\u003e or \u003cstrong data-end=\"1928\" data-start=\"1912\"\u003esingle-ended\u003c\/strong\u003e amplifiers, these Baldwin\/Sylvania EL84s deliver \u003cstrong data-end=\"2016\" data-start=\"1984\"\u003esmooth, natural musicality\u003c\/strong\u003e while maintaining \u003cstrong data-end=\"2076\" data-start=\"2029\"\u003equiet operation and tonal accuracy\u003c\/strong\u003e .\u003cbr data-end=\"2080\" data-start=\"2077\"\u003ePerfect in vintage American or European gear (Dynaco, Eico, Leak, Fisher), they deliver a balanced, effortless sonic presentation, with an extraordinarily natural and transparent midrange.\u003c\/p\u003e\n\u003cp data-end=\"2322\" data-start=\"2286\"\u003e🎸 \u003cstrong data-end=\"2322\" data-start=\"2289\"\u003eUse in Music Amplifiers\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-end=\"2778\" data-start=\"2324\"\u003eIn the musical field, they offer a \u003cstrong data-end=\"2388\" data-start=\"2361\"\u003eharmonious, warm and full\u003c\/strong\u003e sound, with generous headroom and constant dynamic response even under load.\u003cbr data-end=\"2463\" data-start=\"2460\"\u003eParticularly suitable for \u003cstrong data-end=\"2523\" data-start=\"2506\"\u003eVox AC15\/AC30\u003c\/strong\u003e , \u003cstrong data-end=\"2541\" data-start=\"2525\"\u003eMarshall 18W\u003c\/strong\u003e , \u003cstrong data-end=\"2556\" data-start=\"2543\"\u003eMatchless\u003c\/strong\u003e amplifiers, or boutique replicas, where their \u003cstrong data-end=\"2618\" data-start=\"2592\"\u003eAmerican sound texture\u003c\/strong\u003e provides body, sustain and definition in the harmonics.\u003cbr data-end=\"2678\" data-start=\"2675\"\u003eThe low background noise also makes them excellent for \u003cstrong data-end=\"2753\" data-start=\"2733\"\u003estudio recording\u003c\/strong\u003e and \u003cstrong data-end=\"2777\" data-start=\"2756\"\u003eprofessional use\u003c\/strong\u003e .\u003c\/p\u003e\n\u003cp data-end=\"2820\" data-start=\"2785\"\u003e🎯 \u003cstrong data-end=\"2820\" data-start=\"2788\"\u003eNote for Audiophiles and Technicians\u003c\/strong\u003e\u003cstrong data-end=\"2869\" data-start=\"2824\"\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-end=\"3312\" data-start=\"3183\"\u003eA quartet with a \u003cstrong data-end=\"3238\" data-start=\"3210\"\u003enoble, warm and natural\u003c\/strong\u003e character, capable of combining \u003cstrong data-end=\"3311\" data-start=\"3260\"\u003etimbre precision and authentic vintage charm\u003c\/strong\u003e .\u003c\/p\u003e\n\u003chr data-end=\"3317\" data-start=\"3314\"\u003e\n\u003cp data-end=\"3344\" data-start=\"3319\"\u003e\u003cstrong data-end=\"3344\" data-start=\"3322\"\u003eTest Results\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-end=\"3542\" data-start=\"3346\"\u003eValves tested on \u003cstrong data-end=\"3398\" data-start=\"3365\"\u003eAmplitrex AT-1000\u003c\/strong\u003e Tube Tester\u003cbr data-end=\"3401\" data-start=\"3398\"\u003e\u003cstrong data-end=\"3424\" data-start=\"3401\"\u003eTest conditions:\u003c\/strong\u003e Va = 250 V, Vg = –8 V\u003cbr data-end=\"3449\" data-start=\"3446\"\u003e\u003cstrong data-end=\"3471\" data-start=\"3449\"\u003e100% average value:\u003c\/strong\u003e Gm = 11.3 ; Ia = 48 mA\u003cbr data-end=\"3502\" data-start=\"3499\"\u003e\u003cstrong data-end=\"3528\" data-start=\"3502\"\u003eTest Result:\u003c\/strong\u003e STRONG\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eValve 1:\u003c\/strong\u003e Gm = 9.6 ; Ia = 41.4 mA\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eValve 2:\u003c\/strong\u003e Gm = 10.2 ; Ia = 42.6 mA\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eValve 3:\u003c\/strong\u003e Gm = 9.8 ; Ia = 39.2 mA\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eValve 4:\u003c\/strong\u003e Gm = 9.8 ; Ia = 38.0 mA\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cdiv class=\"_tableContainer_1rjym_1\"\u003e\n\u003cdiv class=\"group _tableWrapper_1rjym_13 flex w-fit flex-col-reverse\" tabindex=\"-1\"\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cp\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e Low. Tested and approved for use in hi-fi and guitar amplifiers.\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eOutput Quality:\u003c\/strong\u003e Excellent – Strong and stable output, no fluctuations.\u003cstrongr\u003e\u003c\/strongr\u003e\u003c\/li\u003e\n\u003cli\u003eShort circuits and GAS: Absent.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr data-end=\"3871\" data-start=\"3868\"\u003e\n\u003ch3\u003e\u003cstrong\u003eConditions:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eCondition:\u003c\/strong\u003e \u003cspan\u003eVintage tubes - Tested and in perfect working order. Shipped in our custom box for optimal protection.\u003c\/span\u003e\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eFunctionality:\u003c\/strong\u003e Fully functional.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eAesthetic condition:\u003c\/strong\u003e \u003cspan\u003eVery good – Clearly legible writing with minor signs of wear, no obvious defects. See photos for details.\u003c\/span\u003e\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eManufacturing Code:\u003cspan\u003e\u0026nbsp;\u003c\/span\u003e\u003c\/strong\u003e312 526 → 312 indicates the manufacturer, i.e. Sylvania Electric Products Inc., Emporium, Pa. - 526 → 5 (out of three digits) → 1955 - 26 → 26th week of the year\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca rel=\"noopener\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"SYLVANIA","offers":[{"title":"Default Title","offer_id":42983318323447,"sku":"00697","price":129.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_23c984be-7a0d-4078-a472-952cb470926d.jpg?v=1760471063"},{"product_id":"6v6gt-channel-master-gray-plates-getter-tested-tubes-made-in-japan","title":"6V6GT CHANNEL MASTER Gray Plates [] Getter Tested Tubes MADE IN JAPAN","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cstrong\u003e6V6 GT CHANNEL MASTER Gray Plates Square Getter Tested Tubes\u003c\/strong\u003e\u003cbr\u003e \u003cstrong\u003eMADE IN JAPAN\u003c\/strong\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003ch3\u003e \u003cstrong\u003eDescription:\u003c\/strong\u003e\n\u003c\/h3\u003e\n\u003cp data-end=\"485\" data-start=\"85\"\u003e This \u003cstrong data-end=\"146\" data-start=\"121\"\u003eJapanese-made\u003c\/strong\u003e \u003cstrong data-end=\"116\" data-start=\"92\"\u003e6V6GT Channel Master\u003c\/strong\u003e represents one of the most interesting non-US interpretations of one of the most beloved power tubes of all time. Made with \u003cstrong data-end=\"292\" data-start=\"277\"\u003egray plates\u003c\/strong\u003e and \u003cstrong data-end=\"312\" data-start=\"295\"\u003esquare getters\u003c\/strong\u003e , it displays a solid and tidy construction, typical of quality Japanese productions, often underestimated but capable of excellent sonic performance and great reliability.\u003c\/p\u003e\n\u003cp data-end=\"604\" data-start=\"487\"\u003e The valve has been \u003cstrong data-end=\"540\" data-start=\"506\"\u003etested in our laboratory\u003c\/strong\u003e and found to be fully efficient, stable and ready for use.\u003c\/p\u003e\n\u003ch3 data-end=\"631\" data-start=\"611\"\u003e \u003cstrong\u003eSound Character\u003c\/strong\u003e\n\u003c\/h3\u003e\n\u003cp data-end=\"757\" data-start=\"633\"\u003e \u003cstrong data-end=\"642\" data-start=\"633\"\u003eBass\u003c\/strong\u003e\u003cbr data-end=\"645\" data-start=\"642\"\u003e Compact and well-controlled, with a dry and coherent response. Not intrusive, but always present and legible.\u003c\/p\u003e\n\u003cp data-end=\"938\" data-start=\"759\"\u003e \u003cstrong data-end=\"767\" data-start=\"759\"\u003eMedium\u003c\/strong\u003e\u003cbr data-end=\"770\" data-start=\"767\"\u003e Balanced and musical, with a natural delivery that enhances voices and instruments without excessive coloration. A pleasant timbre that integrates well into the overall context.\u003c\/p\u003e\n\u003cp data-end=\"1104\" data-start=\"940\"\u003e \u003cstrong data-end=\"948\" data-start=\"940\"\u003eHigh\u003c\/strong\u003e\u003cbr data-end=\"951\" data-start=\"948\"\u003e Clean and tidy, with good extension and a correct grain. Never aggressive, they maintain a smooth and listenable character even at high volumes.\u003c\/p\u003e\n\u003cp data-end=\"1228\" data-start=\"1106\"\u003e \u003cstrong data-end=\"1118\" data-start=\"1106\"\u003eDynamics\u003c\/strong\u003e\u003cbr data-end=\"1121\" data-start=\"1118\"\u003e Smooth and even, with a prompt response that makes this 6V6GT suitable for both hi-fi and musical contexts.\u003c\/p\u003e\n\u003cp data-end=\"1348\" data-start=\"1230\"\u003e \u003cstrong data-end=\"1244\" data-start=\"1230\"\u003eSoundstage\u003c\/strong\u003e\u003cbr data-end=\"1247\" data-start=\"1244\"\u003e Well-proportioned and stable, with a coherent soundstage and correct separation of elements.\u003c\/p\u003e\n\u003ch3 data-end=\"1388\" data-start=\"1355\"\u003e 🎧 Use in Hi-Fi Amplifiers\u003c\/h3\u003e\n\u003cp data-end=\"1402\" data-start=\"1389\"\u003e Suitable for:\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli data-end=\"1459\" data-start=\"1405\"\u003e single-ended or push-pull amplifiers based on 6V6\u003c\/li\u003e\n\n\u003cli data-end=\"1508\" data-start=\"1462\"\u003e vintage projects and modern reinterpretations\u003c\/li\u003e\n\n\u003cli data-end=\"1575\" data-start=\"1511\"\u003e systems that prioritize musicality, balance, and reliability\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp data-end=\"1661\" data-start=\"1577\"\u003e An interesting choice for those who want a 6V6 with a correct and versatile character.\u003c\/p\u003e\n\u003ch3 data-end=\"1703\" data-start=\"1668\"\u003e 🎸 Use in Music Applications\u003c\/h3\u003e\n\u003cp data-end=\"1726\" data-start=\"1704\"\u003e Highly commendable in:\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli data-end=\"1769\" data-start=\"1729\"\u003e guitar amplifiers and instruments\u003c\/li\u003e\n\n\u003cli data-end=\"1873\" data-start=\"1772\"\u003e circuits that benefit from the classic 6V6 response, with natural compression and good definition\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp data-end=\"1952\" data-start=\"1875\"\u003e It offers a smooth musical performance, with predictable and pleasant behavior.\u003c\/p\u003e\n\u003ch3 data-end=\"1996\" data-start=\"1959\"\u003e 🎯 Note for audiophiles and technicians\u003c\/h3\u003e\n\u003cp data-end=\"2057\" data-start=\"1997\"\u003e This \u003cstrong data-end=\"2042\" data-start=\"2004\"\u003e6V6GT Channel Master Made in Japan\u003c\/strong\u003e is a tube:\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli data-end=\"2097\" data-start=\"2060\"\u003e technically solid and well built\u003c\/li\u003e\n\n\u003cli data-end=\"2137\" data-start=\"2100\"\u003e tested and in perfect working order\u003c\/li\u003e\n\n\u003cli data-end=\"2181\" data-start=\"2140\"\u003e timbre-balanced\u003c\/li\u003e\n\n\u003cli data-end=\"2276\" data-start=\"2184\"\u003e ideal for those looking for a valid and reliable alternative to the most well-known American productions \u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp data-is-only-node=\"\" data-is-last-node=\"\" data-end=\"2427\" data-start=\"2278\"\u003e A proposal that combines \u003cstrong data-end=\"2355\" data-start=\"2302\"\u003econstruction quality, musicality and concrete value\u003c\/strong\u003e , selected to offer an authentic and satisfying listening experience.\u003c\/p\u003e\n\u003chr data-start=\"1954\" data-end=\"1957\"\u003e\n\u003cp\u003e \u003cstrong\u003e\u003cspan\u003eTested with AVO CT 163 Tube tester:\u003c\/span\u003e\u003c\/strong\u003e\u003cbr\u003e \u003cspan\u003eVf = 6.3V; Va = 250V; Vg2 = 250V; Vg1 = -12.5V\u003c\/span\u003e\u003cbr\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cspan\u003eAverage 100% Gm = 4.1 ; Ia = 45 mA\u003c\/span\u003e\u003cbr\u003e \u003cstrong\u003eTEST RESULT: VERY STRONG\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e \u003cspan\u003eGm = 4.2 ; Ia = 40 mA\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e \u003cspan\u003eFurther tests performed:\u003c\/span\u003e\u003cbr\u003e \u003cspan\u003eMicrophone Test\u003c\/span\u003e\u003cbr\u003e \u003cspan\u003eEmission Quality\u003c\/span\u003e\u003cbr\u003e \u003cspan\u003eShort Circuit Test\u003c\/span\u003e\u003cspan\u003e\u003c\/span\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/p\u003e","brand":"CHANNEL MASTER","offers":[{"title":"Default Title","offer_id":42987435294967,"sku":"00467","price":16.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/products\/6v6gt-channel-master-gray-plates-getter-tested-tubes-made-in-japan-378469.jpg?v=1657112763"},{"product_id":"6bq5-el84-sylvania-for-hammond-black-plates-matched-tubes-made-in-usa-66","title":"6BQ5 EL84 SYLVANIA for Hammond Matched Pair Black Plates Tubes Made in USA '64","description":"\u003cp\u003e\u003cstrong\u003e6BQ5 ( EL84 ) SYLVANIA for Hammond Matched Pair Black Plates Tubes Made in USA '64\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-start=\"0\" data-end=\"706\"\u003eThis \u003cstrong data-start=\"37\" data-end=\"91\"\u003ematched pair of 6BQ5 \/ EL84 SYLVANIA for Hammond\u003c\/strong\u003e , \u003cstrong data-start=\"104\" data-end=\"124\"\u003eMade in USA production 1964\u003c\/strong\u003e , belongs to one of the most sought-after series supplied by Sylvania for Hammond organs of the time, famous for reliability, rigorous selection and above-average durability.\u003cbr data-start=\"299\" data-end=\"302\"\u003eThe units feature \u003cstrong data-start=\"327\" data-end=\"343\"\u003eblack plates\u003c\/strong\u003e , solid construction and typically American build quality, designed to ensure operational stability even under continuous use. \u003cbr data-start=\"500\" data-end=\"503\"\u003eThe pair is selected as a \u003cstrong data-start=\"532\" data-end=\"548\"\u003eMatched Pair\u003c\/strong\u003e for coherent electrical behavior and uniform tonal response, ideal for hi-fi amplifiers and for restorations of vintage American organs and amplifiers.\u003c\/p\u003e\n\u003cp data-start=\"708\" data-end=\"889\"\u003e\u003cstrong data-start=\"710\" data-end=\"736\"\u003eSound Characteristics\u003c\/strong\u003e\u003cbr data-start=\"736\" data-end=\"739\"\u003eThe timbre of the Sylvania EL84\/6BQ5 with black plates is lively, musical and well-balanced, with a defined character and remarkable dynamic capacity.\u003c\/p\u003e\n\u003cp data-start=\"891\" data-end=\"1041\"\u003e\u003cstrong data-start=\"891\" data-end=\"900\"\u003eBass\u003c\/strong\u003e\u003cbr data-start=\"900\" data-end=\"903\"\u003eTight, fast, and controlled. The low range is precise and solid, with excellent rhythmic and articulation capabilities without bloating.\u003c\/p\u003e\n\u003cp data-start=\"1043\" data-end=\"1237\"\u003e\u003cstrong data-start=\"1043\" data-end=\"1051\"\u003eMedium\u003c\/strong\u003e\u003cbr data-start=\"1051\" data-end=\"1054\"\u003eClear, rich in harmonics, and very natural. Vocals emerge with presence and good texture, while acoustic and jazz instruments benefit from a bright, well-refined midrange.\u003c\/p\u003e\n\u003cp data-start=\"1239\" data-end=\"1410\"\u003e\u003cstrong data-start=\"1239\" data-end=\"1247\"\u003eHigh\u003c\/strong\u003e \u003cbr data-start=\"1247\" data-end=\"1250\"\u003eOpen, fluid, and well-extended. No harshness, clean, detailed highs with a controlled brilliance typical of the best Sylvania productions of the era.\u003c\/p\u003e\n\u003cp data-start=\"1412\" data-end=\"1623\"\u003e\u003cstrong data-start=\"1412\" data-end=\"1424\"\u003eDynamics\u003c\/strong\u003e\u003cbr data-start=\"1424\" data-end=\"1427\"\u003eLively, responsive, and with plenty of headroom. The black plates deliver a crisp, linear, and stable response even under load, making them excellent for amplifiers requiring precision and responsiveness.\u003c\/p\u003e\n\u003cp data-start=\"1625\" data-end=\"1768\"\u003e\u003cstrong data-start=\"1625\" data-end=\"1639\"\u003eSoundstage\u003c\/strong\u003e\u003cbr data-start=\"1639\" data-end=\"1642\"\u003eWide, defined, and realistic soundstage. Good depth and instrument separation, with a stable and uncluttered soundstage.\u003c\/p\u003e\n\u003cp data-start=\"1770\" data-end=\"1826\"\u003e🎧 \u003cstrong data-start=\"1773\" data-end=\"1810\"\u003eUse in Hi-Fi Stereo Amplifiers\u003c\/strong\u003e\u003cbr data-start=\"1810\" data-end=\"1813\"\u003eIdeal for:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli data-start=\"1829\" data-end=\"1891\"\u003eAmerican and European amplifiers using real EL84s,\u003c\/li\u003e\n\u003cli data-start=\"1894\" data-end=\"1935\"\u003erestorations of vintage Hammond equipment,\u003c\/li\u003e\n\u003cli data-start=\"1938\" data-end=\"1979\"\u003esingle-ended and push-pull amplifiers,\u003c\/li\u003e\n\u003cli data-start=\"1982\" data-end=\"2030\"\u003esystems that require transparency and dynamics.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"2032\" data-end=\"2145\"\u003eThe character of Sylvania black plates is particularly suitable for jazz, classical, acoustic and vocal music.\u003c\/p\u003e\n\u003cp data-start=\"2147\" data-end=\"2230\"\u003e🎸 \u003cstrong data-start=\"2150\" data-end=\"2183\"\u003eUse in Music Amplifiers\u003c\/strong\u003e\u003cbr data-start=\"2183\" data-end=\"2186\"\u003eParticularly effective in amplifiers:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli data-start=\"2233\" data-end=\"2243\"\u003eHammond,\u003c\/li\u003e\n\u003cli data-start=\"2246\" data-end=\"2263\"\u003evintage Gibson,\u003c\/li\u003e\n\u003cli data-start=\"2266\" data-end=\"2297\"\u003eEL84 style boutique projects,\u003c\/li\u003e\n\u003cli data-start=\"2300\" data-end=\"2351\"\u003eamplifiers with hot bias or moderate voltages.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"2353\" data-end=\"2370\"\u003eStrengths:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli data-start=\"2373\" data-end=\"2407\"\u003emusical and progressive break-up,\u003c\/li\u003e\n\u003cli data-start=\"2410\" data-end=\"2443\"\u003erich and controlled harmonics,\u003c\/li\u003e\n\u003cli data-start=\"2446\" data-end=\"2463\"\u003eexcellent sustain,\u003c\/li\u003e\n\u003cli data-start=\"2466\" data-end=\"2507\"\u003etight and well-defined response on the strings.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"2509\" data-end=\"2620\"\u003e🎯 \u003cstrong data-start=\"2512\" data-end=\"2544\"\u003eNote for audiophiles and technicians\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"2509\" data-end=\"2620\"\u003eAn ideal pair for restorations, upgrades or use in hi-fi and music amplifiers requiring robust, musical and coherent EL84s.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eValve tested on \u003cstrong\u003eAMPLITREX AT-1000\u003c\/strong\u003e Tube Tester:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eTest Conditions:\u003c\/strong\u003e \u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003eVa = 250V, Vg2 = 250V, Vg = -7.3V\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eAverage 100%:\u003c\/strong\u003e \u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003eGm = 11.3 ; Ia = 48 mA\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eTest Result:\u003c\/strong\u003e VERY STRONG\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eValve 1:\u003c\/strong\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cspan\u003eGm = 9.4 ; Ia = 40.2 mA\u003c\/span\u003e\u003cstrong\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003eValve 2:\u003c\/strong\u003e\u003c\/span\u003e \u003cmeta charset=\"utf-8\"\u003eGm = 9.5 ; Ia = 40.2 mA\u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cdiv\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/div\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e Low. Tested and approved for use in hi-fi and guitar amplifiers.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eOutput Quality:\u003c\/strong\u003e Excellent – Very strong and stable output, no fluctuations.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eShort circuits and GAS:\u003c\/strong\u003e Absent.\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eConditions:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eCondition:\u003c\/strong\u003e Vintage tubes - Tested and in perfect working order. Shipped in our custom box for optimal protection.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eFunctionality:\u003c\/strong\u003e Fully functional.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eAesthetic condition:\u003c\/strong\u003e Very good – Clearly legible writing with minor signs of wear, no obvious defects. See photos for details.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eManufacturing Code:\u003c\/strong\u003e\u003cstrong\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e312 64-13 → 312 indicates the manufacturer, i.e., Sylvania Electric Products Inc., Emporium, Pa. - 64-13 → RMA\/EIA Open Date Code → manufactured 13th week of 1964\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"SYLVANIA","offers":[{"title":"Default Title","offer_id":43657424601335,"sku":"01063","price":79.9,"currency_code":"EUR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/2_0354cdd9-7c30-497b-b4c5-381d0f88e3ce.jpg?v=1765466833"},{"product_id":"5881-6l6wgb-ge-brown-base-side-oo-getter-matched-tubes-made-in-canada","title":"6L6WGB \/ 5881 GE Matched Quad Brown Base Side OO Getter Tubes Made in CANADA @ TEST NOS","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cstrong\u003e6L6WGB \/ 5881 GE Matched Quad Brown Base Side OO Getter Tubes Made in CANADA @ TEST NOS\u003c\/strong\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-end=\"1070\" data-start=\"479\"\u003eThis matched quartet of GE-branded 5881s, produced in Canadian factories in the late 1950s, represents one of the most respected versions of the 6L6WGB. Construction includes \u003cstrong data-end=\"719\" data-start=\"694\"\u003eblack solid plates\u003c\/strong\u003e , \u003cstrong data-end=\"762\" data-start=\"721\"\u003edual 'OO'-shaped side getters\u003c\/strong\u003e , and \u003cstrong data-end=\"795\" data-start=\"766\"\u003ea brown Bakelite base\u003c\/strong\u003e , a hallmark of high-quality military and OEM supplies.\u003cbr data-end=\"864\" data-start=\"861\"\u003eThe tubes are \u003cstrong data-end=\"918\" data-start=\"880\"\u003eused but tested with NOS values\u003c\/strong\u003e , and are perfectly matched to each other for anode current and transconductance, ensuring sonic consistency and technical reliability in every application.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eTimbre\u0026nbsp;characteristics:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-end=\"1354\" data-start=\"1132\"\u003e\u003cstrong data-end=\"1142\" data-start=\"1132\"\u003eBass:\u003c\/strong\u003e\u003cbr data-end=\"1145\" data-start=\"1142\"\u003eTight, controlled, and precise. The low end of the 5881 GE is less explosive than that of modern 6L6GCs, but gains in articulation and definition. Perfect for detailed listening or fast, dry bass.\u003c\/p\u003e\n\u003cp data-end=\"1567\" data-start=\"1356\"\u003e\u003cstrong data-end=\"1365\" data-start=\"1356\"\u003eMedium:\u003c\/strong\u003e\u003cbr data-end=\"1368\" data-start=\"1365\"\u003eBalanced, dynamic, and natural. The mids emerge with fluidity and great coherence, offering a neutral yet never sterile timbre. Vocals are rendered realistically and pleasantly, without artificial coloration.\u003c\/p\u003e\n\u003cp data-end=\"1752\" data-start=\"1569\"\u003e\u003cstrong data-end=\"1578\" data-start=\"1569\"\u003eHighs:\u003c\/strong\u003e\u003cbr data-end=\"1581\" data-start=\"1578\"\u003eDelicate and well-extended. The highs are silky, well-integrated, and never invasive. Detail is present but not aggressive, with a fine grain that favors prolonged listening.\u003c\/p\u003e\n\u003cp data-end=\"1926\" data-start=\"1754\"\u003e\u003cstrong data-end=\"1767\" data-start=\"1754\"\u003eDynamics:\u003c\/strong\u003e\u003cbr data-end=\"1770\" data-start=\"1767\"\u003eResponsive and fluid, with excellent microdynamics. Transient response is natural and precise, making the 5881 ideal for those seeking expressiveness without excess.\u003c\/p\u003e\n\u003cp data-end=\"2142\" data-start=\"1928\"\u003e\u003cstrong data-end=\"1943\" data-start=\"1928\"\u003eSoundstage:\u003c\/strong\u003e\u003cbr data-end=\"1946\" data-start=\"1943\"\u003eCoherent and three-dimensional. The soundstage opens up with order and depth, offering good separation between instruments and vocals. Excellent positioning of sound sources and well-managed spatiality.\u003c\/p\u003e\n\u003ch3 data-end=\"2201\" data-start=\"2149\"\u003e🎧 Use in Push-Pull Stereo Hi-Fi Amplifiers\u003c\/h3\u003e\n\u003cp data-end=\"2603\" data-start=\"2202\"\u003eIdeal for stereo or integrated amplifiers based on push-pull topologies, these GE 5881s are perfect for vintage or modern projects. They offer \u003cstrong data-end=\"2416\" data-start=\"2382\"\u003ea balanced and musical sound\u003c\/strong\u003e , with low noise, excellent control and a classic yet refined sonic signature. Particularly suitable for medium-high efficiency systems or for those who prefer a transparent yet warm sound.\u003c\/p\u003e\n\u003ch3 data-end=\"2660\" data-start=\"2610\"\u003e🎸 Use in Guitar and Bass Amplifiers\u003c\/h3\u003e\n\u003cp data-end=\"3019\" data-start=\"2661\"\u003eThe 5881 GE Canada is a popular choice in Fender blackface and brownface circuits (such as the Bassman, Bandmaster, Pro). They offer \u003cstrong data-end=\"2825\" data-start=\"2784\"\u003eprogressive harmonic compression\u003c\/strong\u003e , \u003cstrong data-end=\"2857\" data-start=\"2827\"\u003eclean, dynamic headroom\u003c\/strong\u003e , and \u003cstrong data-end=\"2892\" data-start=\"2865\"\u003econtrolled saturation\u003c\/strong\u003e , ideal for jazz, blues, and “American” cleans. They are also excellent for boutique projects seeking a reliable, vintage voice.\u003c\/p\u003e\n\u003ch3 data-end=\"3063\" data-start=\"3026\"\u003e🎯 Note for audiophiles and technicians\u003c\/h3\u003e\n\u003cp data-end=\"3380\" data-start=\"3064\"\u003eThe 5881 GE Canada offers \u003cstrong data-end=\"3134\" data-start=\"3090\"\u003eone of the most balanced and honest sounds\u003c\/strong\u003e of the 6L6 family: musicality, stability, and a natural voice that never tires. The sturdy construction and stable electrical characteristics make this matched quartet ideal for restorations, upgrades, and everyday use in demanding systems.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eTested on\u003cmeta charset=\"utf-8\"\u003e AVO VCM 163 Tube tester:\u003c\/strong\u003e\u003c\/span\u003e \u003cbr\u003eVf = 6.3V; Va = 300V; Vg2 = 200V; Vg = -12.5V\u003cbr\u003eAverage 100% Gm = 5300 ; Ia = 48 mA\u003cbr\u003e\u003cstrong\u003eTEST RESULT:\u003c\/strong\u003e \u003cstrong\u003eVERY STRONG\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eValve 1: Gm = 5350 ; Ia = 54 mA\u003c\/li\u003e\n\u003cli\u003eValve 2: Gm = 5250 ; Ia = 53 mA\u003c\/li\u003e\n\u003cli\u003eValve 3: Gm = 5250 ; Ia = 54 mA\u003c\/li\u003e\n\u003cli\u003eValve 4: Gm = 5200 ; Ia = 57 mA\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cdiv\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/div\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e\u003cmeta charset=\"utf-8\"\u003e Standard. Tested and approved for use in hi-fi and guitar amplifiers.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eOutput Quality:\u003c\/strong\u003e Excellent – Very strong and stable output, no fluctuations.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eShort circuits and GAS:\u003c\/strong\u003e Absent.\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eConditions:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eCondition:\u003c\/strong\u003e Vintage tubes - Tested and in perfect working order. Shipped in our custom box for optimal protection.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eFunctionality:\u003c\/strong\u003e Fully functional.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eCosmetic condition:\u003c\/strong\u003e Excellent – Excellently preserved lettering, minimal signs of wear. See photos for details.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eManufacturing Code:\u003c\/strong\u003e KT - Manufactured in CANADA in July 1964\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"GE","offers":[{"title":"Default Title","offer_id":43659321245943,"sku":"01069","price":229.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/products\/5881-6l6wgb-ge-brown-base-side-oo-getter-matched-tubes-made-in-canada-at-test-nos-394624.jpg?v=1671130174"},{"product_id":"2a3-rca-black-carbon-plates-bottom-dd-getters-matched-tube-made-in-usa","title":"SX182B SYLVANIA NOS NIB Black Plates Bottom Getter Tested Tube Made in USA","description":"\u003cp\u003e\u0026nbsp;\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eSX182B (482B\/582B ) SYLVANIA NOS NIB Black Plates Bottom Getter\u0026nbsp;Power Triode\u003c\/strong\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cstrong\u003eMade in USA '20s\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eSYLVANIA's first leaf tube, straight from the \"Charleston\" era, still in its original packaging. The valve base is firm and there are no loose particles inside.\u003c\/strong\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cbr data-mce-fragment=\"1\"\u003eTested with AVO\u0026nbsp;CT 160 Tube tester:\u003cbr data-mce-fragment=\"1\"\u003eOur instruments are calibrated with reference tubes.\u003cbr data-mce-fragment=\"1\"\u003eVf = 2.5V; Va = 250V; Vg = -35V \u003cbr data-mce-fragment=\"1\"\u003eAverage 100% Gm =\u0026nbsp;1500\u0026nbsp;; Ia = 18 mA\u003cbr data-mce-fragment=\"1\"\u003e\u003cstrong\u003eTEST RESULT: VERY STRONG\u003c\/strong\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003c\/p\u003e\n\u003cp\u003eGm =\u0026nbsp;1800 ; Ia =\u0026nbsp;16 mA\u003c\/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c\/p\u003e\n\u003cp\u003eFurther tests performed:\u003cbr data-mce-fragment=\"1\"\u003eEmission quality\u003cbr data-mce-fragment=\"1\"\u003eShort circuit test\u003cbr\u003e\u003c\/p\u003e","brand":"SYLVANIA","offers":[{"title":"Default Title","offer_id":46476204573020,"sku":"01314","price":189.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/products\/1_05d57a36-c75f-4c1e-a912-fe6f5fa33169.jpg?v=1680889430"},{"product_id":"el37-6l6g-mullard-blackburn-labeled-brimar-dual-halo-getter-test-very-strong-tube-made-in-gt-britain","title":"EL37 ( 6L6G ) MULLARD Blackburn labeled BRIMAR Dual Halo Getter Test Very Strong Tube Made in GT. Britain","description":"\u003cp\u003e\u003cstrong\u003eEL37 ( 6L6G ) MULLARD Blackburn labeled BRIMAR Dual Halo Getter Tested Tube Made in GT. Britain\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eValve produced by \u003cmeta charset=\"utf-8\"\u003eMULLARD in the Blackburn factory in the U.K. in September 1963\u003cbr\u003e\u003cbr\u003eTested with AVO VCM 163 Tube tester with 10 minute warm-up.\u003cbr\u003eOur instruments are calibrated with reference tubes.\u003cbr\u003eVf = 6.3V; Va = 250V; Vg2 = 250V;\u0026nbsp;Vg = -13.5V\u003cbr\u003eAverage 100% Gm =\u0026nbsp;11000\u0026nbsp;; Ia =\u0026nbsp;100\u0026nbsp;mA\u003cbr\u003e\u003cstrong\u003eTEST RESULT: VERY STRONG\u003c\/strong\u003e\u003cbr\u003e\u003cbr\u003eGm =\u0026nbsp;10300 ; Ia = 82 mA\u003cbr\u003e\u003cbr\u003eFurther tests performed:\u003cbr\u003eMicrophony Test\u003cbr\u003eEmission Quality\u003cbr\u003eShort Circuit Test\u003cbr\u003e\u003c\/p\u003e","brand":"MULLARD","offers":[{"title":"Default Title","offer_id":46500115743068,"sku":"01362","price":179.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/products\/1_a4135ee1-4fae-42ca-a020-02b20d034f8c.jpg?v=1682062845"},{"product_id":"5881-6l6wgb-rca-brown-base-matched-tubes-made-in-usa","title":"5881 ( 6L6WGB ) RCA Brown Base Matched Pair Vacuum Tubes Made in USA","description":"\u003cp\u003e\u003cstrong\u003e5881 ( 6L6WGB ) RCA Brown Base Matched Pair Vacuum Tubes\u003c\/strong\u003e\u003cbr\u003e\u003cspan\u003e\u003cstrong\u003eMADE IN\u0026nbsp;USA\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eThe 5881 is a ruggedized consumer version of comparable military quality.\u0026nbsp;It is known for its excellent music playback capabilities, longevity and solid construction features.\u0026nbsp;\u003c\/span\u003e\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eThese tubes are recommended by OEMs for all TWEED\u0026nbsp;power amplifiers and can be used in Black Face\u0026nbsp;FENDER and other amplifiers, but not above 600V\u0026nbsp;high voltage B+\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eTested\u0026nbsp;with AVO\u0026nbsp;VCM 163 Tube tester:\u003cbr\u003eOur instruments are calibrated with reference tubes.\u003cbr\u003eVf = 6.3V; Va = 300V; Vg2 = 200V; Vg1 = -12.5V\u003cbr\u003eAverage 100% Gm =\u0026nbsp;5300 ; Ia =\u0026nbsp;48 mA\u003cbr\u003e\u003cstrong\u003eTEST RESULT:\u0026nbsp;\u003c\/strong\u003e\u003c\/span\u003e\u003cstrong\u003eVERY STRONG\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eValve 1:\u003cbr\u003eGm =\u0026nbsp;5000 ; Ia =\u0026nbsp;46 mA\u003cbr\u003eValve 2:\u003cbr\u003eGm =\u0026nbsp;5000\u003c\/span\u003e\u0026nbsp;; Ia =\u0026nbsp;47 mA\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eFurther tests performed:\u003cbr\u003eMicrophony Test\u003cbr\u003eEmission Quality\u003cbr\u003eShort Circuit Test\u003c\/span\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/p\u003e","brand":"RCA","offers":[{"title":"Default Title","offer_id":46500872618332,"sku":"01367","price":99.9,"currency_code":"EUR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/products\/1_68093553-0e2d-4c4b-bb44-846cd7b7c2b5.jpg?v=1682093605"},{"product_id":"6bq5-el84-ei-for-hammond-gray-plates-halo-getter-matched-tubes-made-in-yugoslavia","title":"6BQ5 \/ EL84 HAMMOND by Ei Gray Plates Halo Getter Matched Quad Tubes Made in YUGOSLAVIA","description":"\u003ch3 class=\"p1\"\u003e\u003cb\u003e6BQ5 \/ EL84 HAMMOND by Ei – Gray Plates – Halo Getter – Matched Quad – Made in Yugoslavia\u003c\/b\u003e\u003c\/h3\u003e\n\u003cp class=\"p1\"\u003e\u003cb\u003eAMPLITREX Matched Quad – VERY STRONG – Vintage Ei Production for HAMMOND\u003c\/b\u003e\u003c\/p\u003e\n\u003ch3 class=\"p1\"\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp class=\"p2\"\u003eMatched quad of \u003cspan class=\"s1\"\u003e\u003cb\u003e6BQ5 \/ EL84 HAMMOND by Ei Niš\u003c\/b\u003e\u003c\/span\u003e, \u003cspan class=\"s1\"\u003e\u003cb\u003eMade in Yugoslavia\u003c\/b\u003e\u003c\/span\u003e production, selected for hi-fi amplifiers, Hammond compatible, and musical applications requiring four consistent, stable, and vintage European character EL84s.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eThe tubes were produced by \u003cspan class=\"s1\"\u003e\u003cb\u003eElektronska Industrija – Ei\u003c\/b\u003e\u003c\/span\u003e and branded for \u003cspan class=\"s1\"\u003e\u003cb\u003eHAMMOND\u003c\/b\u003e\u003c\/span\u003e, the historic manufacturer of professional electronic organs. The construction features \u003cspan class=\"s1\"\u003e\u003cb\u003eGray Plates\u003c\/b\u003e\u003c\/span\u003e and \u003cspan class=\"s1\"\u003e\u003cb\u003eHalo Getter\u003c\/b\u003e\u003c\/span\u003e, with the same manufacturing code \u003cspan class=\"s1\"\u003e\u003cb\u003eKM4 ◉7I\u003c\/b\u003e\u003c\/span\u003e, a positive detail for production homogeneity and quad consistency.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eThe silk-screening reads \u003cspan class=\"s1\"\u003e\u003cb\u003e“Made in Germany”\u003c\/b\u003e\u003c\/span\u003e, but the manufacturing code \u003cspan class=\"s1\"\u003e\u003cb\u003eKM4 ◉7I\u003c\/b\u003e\u003c\/span\u003e and construction characteristics identify the production as \u003cspan class=\"s1\"\u003e\u003cb\u003eEi Yugoslavia\u003c\/b\u003e\u003c\/span\u003e, consistent with typical European production of the era.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eThe quad has been tested and selected using the \u003cspan class=\"s1\"\u003e\u003cb\u003eAmplitrex AT-1000 Tube Tester\u003c\/b\u003e\u003c\/span\u003e as a \u003cspan class=\"s1\"\u003e\u003cb\u003eMatched Quad\u003c\/b\u003e\u003c\/span\u003e, with a \u003cspan class=\"s1\"\u003e\u003cb\u003eVERY STRONG\u003c\/b\u003e\u003c\/span\u003e result, very close values between the four tubes, stable emission, and \u003cspan class=\"s1\"\u003e\u003cb\u003e48h Burning Test passed\u003c\/b\u003e\u003c\/span\u003e.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eGeneral aesthetic conditions are good. The HAMMOND silk-screening shows normal wear and tear over time, as visible in the photographs, while the internal structures are well preserved.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eSonically, these EL84 Ei tubes offer a lively, musical, and well-articulated sound, with fast and controlled bass, natural and present mids, open highs, and good dynamic response. The matching of the quad promotes a stable soundstage and consistent presentation in compatible push-pull circuits.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eSuitable for EL84 \/ 6BQ5 push-pull amplifiers, vintage integrated amplifiers, Hammond compatible electronics, hi-fi restorations, and musical instrument amplifiers requiring a selected and reliable EL84 quad.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eAn interesting vintage selection for those looking for an authentic, homogeneous, and musically convincing \u003cspan class=\"s1\"\u003e\u003cb\u003eEL84 HAMMOND by Ei\u003c\/b\u003e\u003c\/span\u003e quad, tested and matched by Vacuum Tubes Treasures.\u003c\/p\u003e\n\u003chr\u003e\n\u003cp\u003e\u003cspan\u003eTested on \u003cstrong\u003eAMPLITREX AT-1000\u003c\/strong\u003e Tube tester:\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eVoltage Test:\u003c\/strong\u003e Va = 250V, Vg2 = 250V, Vg1 = -7.3V\u003cbr\u003e\u003cstrong\u003eAverage 100%\u003c\/strong\u003e Gm = 11.3 ; Ia = 48 mA\u003cbr\u003e\u003cstrong\u003eTEST RESULT: VERY STRONG\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eTube 1:\u003c\/strong\u003e Gm 10.90 ; Ia = 47 mA\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eTube 2:\u003c\/strong\u003e Gm 10.90 ; Ia = 47 mA\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eTube 3:\u003c\/strong\u003e Gm 10.87 ; Ia = 43 mA\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eTube 4:\u003c\/strong\u003e Gm 10.55 ; Ia = 42 mA\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eAdditional Tests Performed\u003c\/b\u003e\u003c\/span\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\n\u003cli class=\"p2\"\u003e\n\n\u003cb\u003eBurning Test:\u003c\/b\u003e\u003cspan class=\"s2\"\u003e 48h – OK\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\u003cli class=\"p3\"\u003e\n\n\u003cb\u003eMicrophony:\u003c\/b\u003e Low. Tested and suitable for use in hi-fi and guitar amplifiers.\u003c\/li\u003e\n\n\u003cli class=\"p3\"\u003e\n\n\u003cb\u003eEmission Quality:\u003c\/b\u003e Excellent – very strong and stable emission, without fluctuations.\u003c\/li\u003e\n\n\u003cli class=\"p2\"\u003e\n\n\u003cb\u003eShorts and GAS:\u003c\/b\u003e\u003cspan class=\"s2\"\u003e Absent.\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eConditions\u003c\/b\u003e\u003c\/span\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\n\u003cli class=\"p3\"\u003e\n\n\u003cb\u003eConditions:\u003c\/b\u003e Vintage Tubes - Tested and perfectly functional. Supplied in our custom box for optimal protection.\u003c\/li\u003e\n\n\u003cli class=\"p3\"\u003e\n\n\u003cb\u003eFunctionality:\u003c\/b\u003e Perfectly operational.\u003c\/li\u003e\n\n\u003cli class=\"p3\"\u003e\n\n\u003cb\u003eAesthetic condition:\u003c\/b\u003e Good – Lettering partially worn, but still legible. Tube body in good condition. See photos for details.\u003c\/li\u003e\n\n\u003cli class=\"p2\"\u003e\n\n\u003cb\u003eManufacturing Code: KM4 ◉7I\u003c\/b\u003e\u003cspan class=\"s2\"\u003e → \u003cmeta charset=\"utf-8\"\u003e \u003cb\u003e◉\u003c\/b\u003e indicates the manufacturer, namely \u003cstrong\u003eElektronska industrija\u003c\/strong\u003e\u003c\/span\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003e, YUGOSLAVIA\u003c\/b\u003e\u003c\/span\u003e\u003cspan class=\"s2\"\u003e. \u003cmeta charset=\"utf-8\"\u003e \u003cb\u003e7I\u003c\/b\u003e\u003c\/span\u003e\u003cspan class=\"s2\"\u003e → 7 indicates \u003c\/span\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003e1967\u003c\/b\u003e\u003c\/span\u003e\u003cspan class=\"s2\"\u003e, I indicates the month of September\u003c\/span\u003e\u003cspan class=\"s2\"\u003e.\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e\u003cspan class=\"s2\"\u003e\u003cmeta charset=\"utf-8\"\u003e \u003ca href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" title=\"Perché le nostre valvole sono diverse – il protocollo VTT che migliora suono, affidabilità e durata\" rel=\"noopener\" target=\"_blank\"\u003e\u003cstrong\u003eDiscover why our tubes are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/span\u003e\u003c\/p\u003e","brand":"Ei","offers":[{"title":"Default Title","offer_id":46684615377244,"sku":"01397","price":119.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/4_8cc41f82-9713-440e-88fd-620f2c7837d0.jpg?v=1781601719"},{"product_id":"6888-te-40-sylvania-black-plates-halo-getter-tested-tube-made-in-usa","title":"6888 ( TE-40 ) NOS NIB SYLVANIA Black plates Halo Getter Tested Tube Made in USA","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cstrong\u003e6888 ( TE-40 ) NOS NIB SYLVANIA Black plates Halo Getter Tested Tube \u003c\/strong\u003e\u003cbr\u003e\u003cstrong\u003eMade in USA\u003c\/strong\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan data-mce-fragment=\"1\"\u003eLogos worn as per photo\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan data-mce-fragment=\"1\"\u003eTested on AVO VCM 163 Tube tester:\u003c\/span\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eOur instruments are calibrated with reference tubes.\u003c\/span\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eVoltage Test: Va =\u0026nbsp;150 V; Vg2 =\u0026nbsp;90 V; Vg = 0 V\u003c\/span\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eAverage 100% Ia = 38 mA\u003c\/span\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cstrong\u003eTEST RESULT: VERY STRONG\u003c\/strong\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eAdditional tests performed :\u003c\/span\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eMicrophony Test\u003c\/span\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eEmission Quality\u003c\/span\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eTest for Short Circuits\u003c\/span\u003e\u003cbr\u003e\u003cspan data-mce-fragment=\"1\"\u003eTest for GAS\u003c\/span\u003e\u003c\/p\u003e","brand":"SYLVANIA","offers":[{"title":"Default Title","offer_id":46709412004188,"sku":"01413V","price":9.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_70d7dfeb-0c43-45b6-ab27-2f91a00e4ce5.jpg?v=1684511207"},{"product_id":"copia-del-6888-te-40-nos-nib-sylvania-black-plates-halo-getter-tested-tube-made-in-usa","title":"6888 ( TE-40 ) NOS NIB SYLVANIA Black plates Halo Getter Tested Tube Made in USA","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cstrong\u003e6888 ( TE-40 ) NOS NIB SYLVANIA Black plates Halo Getter Tested Tube \u003c\/strong\u003e\u003cbr\u003e\u003cstrong\u003eMade in USA\u003c\/strong\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan data-mce-fragment=\"1\"\u003eLogos worn as per photo\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan data-mce-fragment=\"1\"\u003eTested on AVO VCM 163 Tube tester:\u003c\/span\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eOur instruments are calibrated with reference tubes.\u003c\/span\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eVoltage Test: Va =\u0026nbsp;150 V; Vg2 =\u0026nbsp;90 V; Vg = 0 V\u003c\/span\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eAverage 100% Ia = 38 mA\u003c\/span\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cstrong\u003eTEST RESULT: VERY STRONG\u003c\/strong\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eAdditional tests performed :\u003c\/span\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eMicrophony Test\u003c\/span\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eEmission Quality\u003c\/span\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eTest for Short Circuits\u003c\/span\u003e\u003cbr\u003e\u003cspan data-mce-fragment=\"1\"\u003eTest for GAS\u003c\/span\u003e\u003c\/p\u003e","brand":"SYLVANIA","offers":[{"title":"Default Title","offer_id":46709470069084,"sku":"01414V","price":9.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_e3d266c6-c42b-41cd-8e35-fb3b3042c2bd.jpg?v=1684512969"},{"product_id":"5881-6l6wgb-tung-sol-brown-base-matched-pair-vacuum-tubes-made-in-usa","title":"5881 ( 6L6WGB ) NOS TUNG-SOL Brown Base Matched Pair Vacuum Tubes Made in USA","description":"\u003cp\u003e\u003cstrong\u003e5881 ( 6L6WGB ) NOS TUNG-SOL Brown Base Matched Pair Vacuum Tubes\u003c\/strong\u003e\u003cbr\u003e\u003cspan\u003e\u003cstrong\u003eMADE IN\u0026nbsp;USA\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eTung-Sol made the best 5881\/6L6WGB ever.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eThe 5881 is a ruggedized consumer version of comparable military quality.\u0026nbsp;It is known for its excellent music playback capabilities, longevity and solid construction features.\u0026nbsp;\u003c\/span\u003e\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eThese tubes are recommended by OEMs for all TWEED\u0026nbsp;power amplifiers and can be used in Black Face\u0026nbsp;FENDER and other amplifiers, but not above 600V\u0026nbsp;high voltage B+\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eTested\u0026nbsp;with AVO\u0026nbsp;VCM 163 Tube tester:\u003c\/strong\u003e\u003cbr\u003eOur instruments are calibrated with reference tubes.\u003cbr\u003eVf = 6.3V; Va = 300V; Vg2 = 200V; Vg1 = -12.5V\u003cbr\u003eAverage 100% Gm =\u0026nbsp;5300 ; Ia =\u0026nbsp;48 mA\u003cbr\u003e\u003cstrong\u003eTEST RESULT:\u0026nbsp;\u003c\/strong\u003e\u003c\/span\u003e\u003cstrong\u003eVERY STRONG\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eValve 1:\u003cbr\u003eGm =\u0026nbsp;4800 ; Ia =\u0026nbsp;46 mA\u003cbr\u003eValve 2:\u003cbr\u003eGm =\u0026nbsp;4800\u003c\/span\u003e\u0026nbsp;; Ia =\u0026nbsp;46 mA\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eFurther tests performed:\u003cbr\u003eMicrophony Test\u003cbr\u003eEmission Quality\u003cbr\u003eTest for Short Circuits\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003eTest for GAS\u003c\/span\u003e\u003c\/p\u003e","brand":"TUNG-SOL","offers":[{"title":"Default Title","offer_id":47129419252060,"sku":"01717","price":229.9,"currency_code":"EUR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_da0d260d-d1e2-4c01-b407-ec521a151b20.jpg?v=1696096132"},{"product_id":"6l6gb-rca-gray-plates-bottom-dd-getter-matched-tubes-made-in-usa","title":"6L6GB RCA Gray Plates Bottom DD Getter Matched Tubes MADE IN USA","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cstrong\u003e6L6GB RCA Gray Plates Bottom DD Getter Matched Quad Tubes MADE IN USA\u003c\/strong\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003e\u003c\/strong\u003e\u003c\/span\u003e \u003cspan\u003eAll tubes are made by RCA USA, identical in appearance and internal structure. They feature the distinctive hexagonal RCA logo. One tube is branded for the Baldwin Piano Company.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e \u003cspan\u003eThe color on the center key of the socket indicates that they were selected directly by RCA for low background noise.\u003cbr\u003e\u003cbr\u003e\u003c\/span\u003e \u003cspan\u003eTested with AVO VCM 163 Tube tester:\u003cbr\u003e Vf = 6.3V; Va = 350V; Vg2 = 250V; Vg = -18V\u003cbr\u003e Average 100% Gm = 5200 ; Ia = 54 mA\u003cbr\u003e \u003cstrong\u003eTEST RESULT: VERY STRONG\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e \u003cspan\u003eValve 1: Gm = 5100 ; Ia = 61 mA\u003cbr\u003e Valve 2: Gm = 5100 ; Ia = 58 mA\u003c\/span\u003e\u003cbr\u003e \u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003eValve 2: Gm = 5000 ; Ia = 54 mA\u003c\/span\u003e\u003cbr\u003e \u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003eValve 2: Gm = 5100 ; Ia = 55 mA\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e \u003cspan\u003eFurther tests performed:\u003cbr\u003e Microphone Test\u003cbr\u003e Emission Quality\u003cbr\u003e Short Circuit Test\u003c\/span\u003e\u003cbr\u003e \u003cspan\u003eGAS Test\u003c\/span\u003e\u003c\/p\u003e","brand":"RCA","offers":[{"title":"Default Title","offer_id":47285600977244,"sku":"00152","price":299.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/s-l1600-1_452d4aa0-aae4-4c87-b0cd-7c41e2da97f5.jpg?v=1699459631"},{"product_id":"copia-del-6v6gt-tung-sol-black-glass-foil-getter-matched-tubes-made-in-usa","title":"6V6 GT TUNG-SOL Black Glass Foil Getter Tested Pair Tubes MADE IN USA '56","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cstrong\u003e6V6 GT TUNG-SOL NOS Black Glass Foil Getter Tested Tube \u003c\/strong\u003e\u003cbr\u003e\u003cstrong\u003eMADE IN USA '56\u003c\/strong\u003e\u003cbr\u003e\u003cbr\u003eThese tubes, produced in the United States in 1956, are particularly appreciated by guitarists for their warm, powerful, and dynamic sound, perfect for use in guitar amplifiers. The Black Glass design and Foil Getter contribute to a unique sonic signature, combining depth, clarity, and remarkable dynamic response.\u003cbr\u003e\u003cbr\u003eThe low-end is rich and well-defined, with bass that provides a solid foundation without being overwhelming. This allows for a full, rounded sound, ideal for punchy and powerful rhythms. Tight and controlled bass makes these tubes perfect for guitarists seeking a robust and precise sound without excessive low-frequency emphasis.\u003cbr\u003e\u003cbr\u003eThe midrange is particularly expressive, with strong and detailed presence that brings guitar tones to life. The 6V6 GT TUNG-SOL delivers a warm and full midrange response, perfect for playing solos rich in nuances and harmonics. Their dynamic response allows for a wide range of tones, from clean and transparent to full and saturated distortions, adapting perfectly to various musical styles, from rock to blues.\u003cbr\u003e\u003cbr\u003eThe high frequencies are smooth and never harsh, maintaining a clarity that allows every detail of the sound to be perceived without causing fatigue. They maintain a balanced response across the entire spectrum, with high frequencies that provide brightness and definition without being sharp or overly present. This characteristic makes them ideal for achieving a bright but not overly aggressive sound, perfect for genres that require a balance between warmth and definition.\u003cbr\u003e\u003cbr\u003eProduced by TUNG-SOL, USA\u003cbr\u003e\u003cbr\u003eData\u0026nbsp;Code: 3226-52\u003cbr\u003e\u003cbr\u003e\u003cstrong\u003eTested with AMPLITREX AT-1000 Tube tester:\u003c\/strong\u003e\u003cbr\u003eOur instruments are calibrated with reference tubes. \u003cbr\u003eVf = 6.3V; Va = 250V; Vg2 = 250V; Vg1 = -12.5V \u003cbr\u003eAverage 100% Gm = 4.1 ; Ia = 45 mA \u003cbr\u003e\u003cstrong\u003eTEST RESULT: VERY STRONG\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eGm = 4.0 ; Ia = 42 mA \u003cbr\u003e\u003cbr\u003eAdditional tests performed:\u003cbr\u003eMicrophonics Test \u003cbr\u003eEmission Quality \u003cbr\u003eShort Circuit Test \u003cbr\u003eGas Test \u003cbr\u003e\u003cbr\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca rel=\"noopener\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003cbr\u003e\u003c\/p\u003e","brand":"TUNG-SOL","offers":[{"title":"Default Title","offer_id":47446049882460,"sku":"01927","price":89.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_c4e5d4b2-3e90-4110-95dd-dcb3024a3066.jpg?v=1728318798"},{"product_id":"6v6-gt-delco-black-glass-foil-getter-by-sylvania-tested-tube-made-in-usa-57","title":"6V6 GT DELCO Black Glass Foil Getter by SYLVANIA Tested Tube Made in USA '48","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cstrong\u003e6V6 GT DELCO Black Glass Foil Getter by SYLVANIA Tested Tube \u003c\/strong\u003e\u003cbr\u003e\u003cstrong\u003eMade in USA '48\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eManufacturing\u0026nbsp;\u003c\/span\u003eSylvania Electric Products Inc., Emporium, Pa.\u003cspan\u003e, USA\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eTested with\u0026nbsp;AMPLITREX AT-1000 Tube tester:\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003eOur instruments are calibrated with reference tubes.\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003eVf = 6.3V; Va = 250V; Vg2 = 250V; Vg1 = -12.5V\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003eAverage 100% Gm = 4100 ; Ia = 45 mA\u003c\/span\u003e\u003cbr\u003e\u003cstrong\u003eTEST RESULT: VERY STRONG\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eGm =\u0026nbsp;4200 ; Ia =\u0026nbsp;39 mA\u003c\/span\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003eFurther tests performed:\u003cbr\u003e\u003cspan\u003eMicrophony Test\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003eEmission Quality\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003eShort Circuit Test\u003c\/span\u003e\u003cbr\u003eGAS Test \u003cbr\u003e\u003cbr\u003e\u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca rel=\"noopener\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/span\u003e\u003cbr\u003e\u003c\/p\u003e","brand":"DELCO","offers":[{"title":"Default Title","offer_id":47499088560476,"sku":"01940Y","price":59.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_885a22c2-c884-4b11-b9a2-ff700c702a8a.jpg?v=1704379604"},{"product_id":"6v6-gt-hytron-black-plates-smoked-glass-getter-tested-tube-made-in-usa-47","title":"6V6 GT HYTRON Black Plates Smoked Glass [] Getter Tested Tube Made in USA '47","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003c!-- x-tinymce\/html --\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e6V6 GT HYTRON Black Plates Smoked Glass Square Getter Tested Tube\u003c\/strong\u003e\u003cbr\u003e\u003cstrong\u003eMade in USA '47\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-start=\"3259\" data-end=\"3886\"\u003eThe \u003cstrong data-start=\"3263\" data-end=\"3293\"\u003e6V6 GT HYTRON Black Plates\u003c\/strong\u003e, featuring \u003cstrong data-start=\"3305\" data-end=\"3339\"\u003eSmoked Glass and Square Getter\u003c\/strong\u003e, was \u003cstrong data-start=\"3345\" data-end=\"3380\"\u003emanufactured in the USA in 1947\u003c\/strong\u003e and is a \u003cstrong data-start=\"3390\" data-end=\"3411\"\u003esingle power tube\u003c\/strong\u003e, ideal for amplifiers \u003cstrong data-start=\"3434\" data-end=\"3475\"\u003edesigned to operate with a single 6V6\u003c\/strong\u003e. Known for its \u003cstrong data-start=\"3491\" data-end=\"3526\"\u003ewarm and harmonically rich tone\u003c\/strong\u003e, it delivers \u003cstrong data-start=\"3540\" data-end=\"3574\"\u003edetailed, musical, and dynamic\u003c\/strong\u003e performance with \u003cstrong data-start=\"3592\" data-end=\"3648\"\u003enatural compression and excellent transient response\u003c\/strong\u003e. The \u003cstrong data-start=\"3654\" data-end=\"3670\"\u003esmoked glass\u003c\/strong\u003e (graphite coating inside the bulb) helps \u003cstrong data-start=\"3712\" data-end=\"3738\"\u003ereduce RF interference\u003c\/strong\u003e and improves thermal stability, while the \u003cstrong data-start=\"3781\" data-end=\"3815\"\u003eblack plates and square getter\u003c\/strong\u003e contribute to \u003cstrong data-start=\"3830\" data-end=\"3864\"\u003ebalanced and harmonically rich\u003c\/strong\u003e sound reproduction.\u003c\/p\u003e\n\u003cul data-start=\"3888\" data-end=\"4669\"\u003e\n\u003cli data-start=\"3888\" data-end=\"4025\"\u003e\u003cstrong data-start=\"3890\" data-end=\"3898\"\u003eBass\u003c\/strong\u003e: \u003cstrong data-start=\"3900\" data-end=\"3931\"\u003eTight, deep, and controlled\u003c\/strong\u003e, providing \u003cstrong data-start=\"3943\" data-end=\"3985\"\u003ea full-bodied yet well-defined low end\u003c\/strong\u003e, adding \u003cstrong data-start=\"3994\" data-end=\"4022\"\u003eweight without muddiness\u003c\/strong\u003e.\u003c\/li\u003e\n\u003cli data-start=\"4026\" data-end=\"4232\"\u003e\u003cstrong data-start=\"4028\" data-end=\"4036\"\u003eMids\u003c\/strong\u003e: \u003cstrong data-start=\"4038\" data-end=\"4082\"\u003eExpressive, detailed, and slightly sweet\u003c\/strong\u003e, delivering a \u003cstrong data-start=\"4097\" data-end=\"4141\"\u003efluid and harmonically rich presentation\u003c\/strong\u003e. Vocals and instruments stand out with \u003cstrong data-start=\"4181\" data-end=\"4229\"\u003eexceptional three-dimensionality and realism\u003c\/strong\u003e.\u003c\/li\u003e\n\u003cli data-start=\"4233\" data-end=\"4391\"\u003e\u003cstrong data-start=\"4235\" data-end=\"4244\"\u003eHighs\u003c\/strong\u003e: \u003cstrong data-start=\"4246\" data-end=\"4280\"\u003eSilky, airy, and well-extended\u003c\/strong\u003e, with \u003cstrong data-start=\"4287\" data-end=\"4329\"\u003ea refined response free from harshness\u003c\/strong\u003e, ensuring \u003cstrong data-start=\"4340\" data-end=\"4388\"\u003eclarity and detail without listening fatigue\u003c\/strong\u003e.\u003c\/li\u003e\n\u003cli data-start=\"4392\" data-end=\"4536\"\u003e\u003cstrong data-start=\"4394\" data-end=\"4406\"\u003eDynamics\u003c\/strong\u003e: \u003cstrong data-start=\"4408\" data-end=\"4428\"\u003eFast and natural\u003c\/strong\u003e, with \u003cstrong data-start=\"4435\" data-end=\"4478\"\u003eprecise and well-articulated transients\u003c\/strong\u003e, creating an \u003cstrong data-start=\"4492\" data-end=\"4516\"\u003eengaging and vibrant\u003c\/strong\u003e sonic experience.\u003c\/li\u003e\n\u003cli data-start=\"4537\" data-end=\"4669\"\u003e\u003cstrong data-start=\"4539\" data-end=\"4553\"\u003eSoundstage\u003c\/strong\u003e: \u003cstrong data-start=\"4555\" data-end=\"4585\"\u003eExpansive and well-defined\u003c\/strong\u003e, with \u003cstrong data-start=\"4592\" data-end=\"4666\"\u003eexcellent instrument separation and a realistic, immersive sonic image\u003c\/strong\u003e.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"4671\" data-end=\"4950\"\u003eWith its \u003cstrong data-start=\"4680\" data-end=\"4725\"\u003erugged construction and careful selection\u003c\/strong\u003e, this \u003cstrong data-start=\"4732\" data-end=\"4762\"\u003e6V6 GT HYTRON Black Plates\u003c\/strong\u003e provides \u003cstrong data-start=\"4772\" data-end=\"4829\"\u003elow microphonics, long lifespan, and stable operation\u003c\/strong\u003e, making it an \u003cstrong data-start=\"4844\" data-end=\"4947\"\u003eideal choice for hi-fi applications and vintage musical instrument amplifiers that use a single 6V6\u003c\/strong\u003e.\u003c\/p\u003e\n\u003chr data-start=\"4952\" data-end=\"4955\"\u003e\n\u003ch3 data-start=\"4957\" data-end=\"4999\"\u003e\u003cstrong data-start=\"4961\" data-end=\"4997\"\u003e📌 Recommended Guitar Amplifiers\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-start=\"5000\" data-end=\"5378\"\u003eSince this is a \u003cstrong data-start=\"5016\" data-end=\"5031\"\u003esingle tube\u003c\/strong\u003e, the \u003cstrong data-start=\"5037\" data-end=\"5054\"\u003e6V6 GT HYTRON\u003c\/strong\u003e is perfect for \u003cstrong data-start=\"5070\" data-end=\"5116\"\u003eamplifiers that run on a single power tube\u003c\/strong\u003e, offering \u003cstrong data-start=\"5127\" data-end=\"5210\"\u003eprogressive saturation, natural compression, and well-balanced dynamic response\u003c\/strong\u003e. Clean tones are \u003cstrong data-start=\"5228\" data-end=\"5249\"\u003ewarm and detailed\u003c\/strong\u003e, while overdrive develops \u003cstrong data-start=\"5276\" data-end=\"5306\"\u003eharmonically and musically\u003c\/strong\u003e, making it an excellent choice for \u003cstrong data-start=\"5342\" data-end=\"5375\"\u003eblues, jazz, and classic rock\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cp data-start=\"5380\" data-end=\"6050\"\u003e🎸 \u003cstrong data-start=\"5383\" data-end=\"5434\"\u003eFender Champ (5F1 Tweed, Blackface, Silverface)\u003c\/strong\u003e – Perfect for \u003cstrong data-start=\"5449\" data-end=\"5504\"\u003erich, harmonic cleans and natural, creamy overdrive\u003c\/strong\u003e.\u003cbr data-start=\"5505\" data-end=\"5508\"\u003e🎸 \u003cstrong data-start=\"5511\" data-end=\"5534\"\u003eGibson GA-5 Skylark\u003c\/strong\u003e – Ideal for \u003cstrong data-start=\"5547\" data-end=\"5604\"\u003esmooth, warm tones with sweet, progressive saturation\u003c\/strong\u003e.\u003cbr data-start=\"5605\" data-end=\"5608\"\u003e🎸 \u003cstrong data-start=\"5611\" data-end=\"5639\"\u003eValco\/Supro 1606 \u0026amp; 1616T\u003c\/strong\u003e – For \u003cstrong data-start=\"5646\" data-end=\"5709\"\u003ea vintage bluesy tone with dynamic and musical light crunch\u003c\/strong\u003e.\u003cbr data-start=\"5710\" data-end=\"5713\"\u003e🎸 \u003cstrong data-start=\"5716\" data-end=\"5741\"\u003eMagnatone Student 107\u003c\/strong\u003e – Offers \u003cstrong data-start=\"5751\" data-end=\"5824\"\u003eairy and detailed sound, great dynamic response, and brilliant cleans\u003c\/strong\u003e.\u003cbr data-start=\"5825\" data-end=\"5828\"\u003e🎸 \u003cstrong data-start=\"5831\" data-end=\"5871\"\u003eSilvertone 1482 (single 6V6 version)\u003c\/strong\u003e – Great for \u003cstrong data-start=\"5884\" data-end=\"5935\"\u003eold-school tones with soft, warm tube overdrive\u003c\/strong\u003e.\u003cbr data-start=\"5936\" data-end=\"5939\"\u003e🎸 \u003cstrong data-start=\"5942\" data-end=\"5969\"\u003eHarmony H303A \u0026amp; Kay 703\u003c\/strong\u003e – Perfect for \u003cstrong data-start=\"5984\" data-end=\"6047\"\u003eauthentic retro tones with natural, characterful saturation\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cp data-start=\"6052\" data-end=\"6266\"\u003eWith its \u003cstrong data-start=\"6061\" data-end=\"6113\"\u003etouch sensitivity and outstanding responsiveness\u003c\/strong\u003e, this \u003cstrong data-start=\"6120\" data-end=\"6150\"\u003e6V6 GT HYTRON Black Plates\u003c\/strong\u003e is an \u003cstrong data-start=\"6157\" data-end=\"6215\"\u003eexcellent choice for single-ended low-power amplifiers\u003c\/strong\u003e, where it can fully express its sonic qualities.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eValve tested on\u003cspan\u003e\u0026nbsp;\u003c\/span\u003e\u003cstrong\u003eAMPLITREX AT-1000\u003c\/strong\u003e\u003cspan\u003e\u0026nbsp;\u003c\/span\u003eTube Tester:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eTest Conditions:\u003c\/strong\u003e\u003cspan\u003e\u0026nbsp;\u003c\/span\u003e\u003cspan\u003eVa = 250V; Vg2 = 250V; Vg = -12.5V\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eAverage 100%:\u003c\/strong\u003e\u003cspan\u003e\u0026nbsp;\u003c\/span\u003e\u003cspan\u003eGm = 4.1 ; Ia = 45 mA\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eTest Result:\u003c\/strong\u003e\u003cspan\u003e\u0026nbsp;\u003c\/span\u003eVERY STRONG\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cmeta charset=\"utf-8\"\u003eValve :\u003c\/strong\u003e\u003cspan\u003e\u0026nbsp;\u003c\/span\u003e\u003cspan\u003eGm = 4,6 ; Ia = 45 mA\u003c\/span\u003e\u003c\/p\u003e\n\u003cdiv\u003e\u003cmeta charset=\"utf-8\"\u003e\n\u003cdiv\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/div\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e\u0026nbsp;Low Noise \u0026amp; Microphonics – Tested and rated for use in hi-fi systems and guitar amplifiers.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eOutput Quality:\u003c\/strong\u003e\u0026nbsp;Excellent – Very strong and stable output, no fluctuations.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eShort circuits and GAS:\u003c\/strong\u003e\u0026nbsp;Absent.\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eConditions:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli data-start=\"221\" data-end=\"371\"\u003e\u003cstrong data-start=\"223\" data-end=\"233\"\u003eCondition:\u003c\/strong\u003e\u003cspan\u003e\u0026nbsp;\u003c\/span\u003eVintage Tubes -\u003cspan\u003e\u0026nbsp;\u003c\/span\u003e\u003cstrong\u003eTested and in perfect working order\u003c\/strong\u003e\u003cspan\u003e\u0026nbsp;\u003c\/span\u003e. Supplied in our custom box for optimum protection.\u003c\/li\u003e\n\u003cli data-start=\"372\" data-end=\"456\"\u003e\u003cstrong data-start=\"374\" data-end=\"391\"\u003eFunctionality:\u003c\/strong\u003e\u003cspan\u003e\u0026nbsp;\u003c\/span\u003e\u003cstrong data-start=\"392\" data-end=\"419\"\u003eFully operational\u003c\/strong\u003e\u003cspan\u003e\u0026nbsp;\u003c\/span\u003e, with excellent test results.\u003c\/li\u003e\n\u003cli data-start=\"457\" data-end=\"672\"\u003e\u003cstrong data-start=\"459\" data-end=\"484\"\u003eCosmetic Condition:\u003c\/strong\u003e\u003cspan\u003e Excellent – Markings perfectly preserved, minimal signs of aging. \u003cstrong\u003eSee pictures for details.\u003c\/strong\u003e\u003c\/span\u003e\u003c\/li\u003e\n\u003cli data-start=\"673\" data-end=\"797\"\u003e\u003cstrong data-start=\"675\" data-end=\"703\"\u003eManufacturing code:\u003c\/strong\u003e\u003cspan\u003e\u0026nbsp;7 - 44\u003c\/span\u003e\u0026nbsp;- Manufactured by \u003cmeta charset=\"utf-8\"\u003e\u003cspan\u003eHytron Radio \u0026amp; Electronics Corp., New York 18, N.Y., USA the\u003c\/span\u003e\u0026nbsp;44th week of 1947\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca rel=\"noopener\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"HYTRON","offers":[{"title":"Default Title","offer_id":47864209178972,"sku":"02097","price":34.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/2_9acd1574-ec38-4c42-abde-d4c61b8fe8e8.jpg?v=1711470834"},{"product_id":"kt66-genalex-matched-pair-smoked-glass-made-in-gt-britain","title":"KT66 GEC \/ Genalex Smoked Glass – Matched Pair – Amplitrex Tested – Made in GT. BRITAIN","description":"\u003cp\u003e \u003cstrong\u003eKT66 GEC \/ Genalex Smoked Glass – Matched Pair – Amplitrex Tested – Made in GT. BRITAIN\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003ch3\u003e \u003cstrong\u003eDescription:\u003c\/strong\u003e\n\u003c\/h3\u003e\n\n\u003cp class=\"p1\"\u003e This \u003cspan class=\"s1\"\u003e\u003cb\u003ematched pair of KT66 GEC \/ Genalex\u003c\/b\u003e\u003c\/span\u003e , \u003cspan class=\"s1\"\u003e\u003cb\u003eMade in Great Britain\u003c\/b\u003e\u003c\/span\u003e , belongs to the historic British production of the absolute reference for power valves. The famous \u003cspan class=\"s1\"\u003e\u003cb\u003eSmoked Glass\u003c\/b\u003e\u003c\/span\u003e construction identifies one of the most iconic and sought-after versions, synonymous with superior construction quality, reliability and collectible prestige.\u003c\/p\u003e\n\n\u003cp class=\"p1\"\u003e The tubes are selected as \u003cspan class=\"s1\"\u003e\u003cb\u003eMatched Pair\u003c\/b\u003e\u003c\/span\u003e and \u003cspan class=\"s1\"\u003e\u003cb\u003etested on AMPLITREX\u003c\/b\u003e\u003c\/span\u003e , guaranteeing electrical coherence, operational stability and uniformity of sound output: a combination that immediately communicates Genalex excellence and authenticity.\u003c\/p\u003e\n\n\u003ch3 class=\"p3\"\u003e \u003cstrong\u003eSound Characteristics\u003c\/strong\u003e\n\u003c\/h3\u003e\n\n \u003cp class=\"p3\"\u003e\u003cb\u003eBass:\u003c\/b\u003e Deep, rounded, and perfectly controlled. The low end is authoritative yet elegant, with solid support that doesn't weigh down the musical message.\u003c\/p\u003e\n\n\u003cp class=\"p3\"\u003e \u003cb\u003eMids:\u003c\/b\u003e The true strength of the British KT66. Rich, fluid, and three-dimensional, with extremely natural vocals and a refined harmonic texture that conveys realism and presence.\u003c\/p\u003e\n\n\u003cp class=\"p3\"\u003e \u003cb\u003eHighs:\u003c\/b\u003e Silky, airy, and well-extended. The highs are refined and never aggressive, with a typical Genalex sweetness that favors long, satisfying listening sessions.\u003c\/p\u003e\n\n\u003cp class=\"p3\"\u003e \u003cb\u003eDynamics:\u003c\/b\u003e Balanced and authoritative. Transient response is prompt but always controlled, with elegant microdynamics and composed macrodynamics.\u003c\/p\u003e\n\n\u003cp class=\"p3\"\u003e \u003cb\u003eSoundstage:\u003c\/b\u003e Wide, deep, and perfectly layered. The soundstage is stable, three-dimensional, and very realistic, with natural instrument placement.\u003c\/p\u003e\n\n\u003ch3 class=\"p3\"\u003e \u003cstrong\u003e\u003cspan class=\"s2\"\u003e🎧\u003c\/span\u003e Use in Hi-Fi Amplifiers\u003c\/strong\u003e\n\u003c\/h3\u003e\n\n\u003cp class=\"p1\"\u003e Ideal for:\u003c\/p\u003e\n\n\u003cul\u003e\n\n\u003cli class=\"p1\"\u003e single-ended and push-pull amplifiers designed for KT66,\u003c\/li\u003e\n\n \u003cli class=\"p1\"\u003ehigh-end British-inspired electronics,\u003c\/li\u003e\n\n\u003cli class=\"p1\"\u003e hi-fi systems that seek musicality, naturalness and timbral refinement.\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cp class=\"p1\"\u003e Particularly suitable for jazz, classical, vocal and high-resolution listening.\u003c\/p\u003e\n\n\u003ch3 class=\"p3\"\u003e \u003cstrong\u003e\u003cspan class=\"s2\"\u003e🎸\u003c\/span\u003e Use in Music Applications\u003c\/strong\u003e\n\u003c\/h3\u003e\n\n\u003cp class=\"p1\"\u003e Also legendary in:\u003c\/p\u003e\n\n\u003cul\u003e\n\n\u003cli class=\"p1\"\u003e British school guitar amplifiers,\u003c\/li\u003e\n\n\u003cli class=\"p1\"\u003e vintage circuits and boutiques,\u003c\/li\u003e\n\n\u003cli class=\"p1\"\u003e contexts where headroom, balance, and a rich, controlled harmonic response are required.\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003ch3 class=\"p3\"\u003e \u003cstrong\u003e\u003cspan class=\"s2\"\u003e🎯\u003c\/span\u003e Note for audiophiles and technicians\u003c\/strong\u003e\n\u003c\/h3\u003e\n\n\u003cp class=\"p3\"\u003e \u003cspan class=\"s2\"\u003eThese\u003c\/span\u003e \u003cb\u003eKT66 GEC \/ Genalex Smoked Glass – Matched Pair\u003c\/b\u003e \u003cspan class=\"s2\"\u003erepresent:\u003c\/span\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n\n\u003cli class=\"p1\"\u003e\n\n \u003cspan class=\"s1\"\u003ethe\u003c\/span\u003e \u003cb\u003emaximum expression of the British KT66\u003c\/b\u003e \u003cspan class=\"s1\"\u003e,\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\u003cli class=\"p1\"\u003e original production \u003cspan class=\"s1\"\u003e\u003cb\u003eMade in Great Britain\u003c\/b\u003e\u003c\/span\u003e ,\u003c\/li\u003e\n\n\u003cli class=\"p1\"\u003e careful selection and \u003cspan class=\"s1\"\u003e\u003cb\u003etesting on AMPLITREX\u003c\/b\u003e\u003c\/span\u003e ,\u003c\/li\u003e\n\n\u003cli class=\"p1\"\u003e first-rate sound, historical and collectible value.\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n \u003cp class=\"p1\"\u003eA pair intended for \u003cspan class=\"s1\"\u003e\u003cb\u003ereference systems and demanding collectors\u003c\/b\u003e\u003c\/span\u003e , for those who want \u003cspan class=\"s1\"\u003e\u003cb\u003ethe authentic Genalex sound\u003c\/b\u003e\u003c\/span\u003e , with all the elegance, musicality and authority that have made these KT66s a timeless legend.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch3\u003e \u003cstrong\u003eTest Results:\u003c\/strong\u003e\n\u003c\/h3\u003e\n\n\u003cp\u003e Tested on\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eAMPLITREX AT-1000\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eTube tester:\u003cbr\u003e \u003cstrong\u003eTest Conditions:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eVa = 350; Vg2 = 250; Vg = -18V\u003cbr\u003e Measurements are taken after approximately 10 minutes of preheating the tubes.\u003cbr\u003e \u003cstrong\u003eAverage 100%:\u003c\/strong\u003e \u003cspan\u003eGm = 5.2 ; Ia = 54 mA\u003c\/span\u003e\u003cbr\u003e \u003cstrong\u003eTEST RESULT:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eVERY STRONG\u003c\/p\u003e\n\n\u003cp\u003e \u003cstrong\u003eValve #1:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eGm = 5.20 ; Ia = 58.2 mA\u003cbr\u003e \u003cstrong\u003eValve #2:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eGm = 5.30 ; Ia =\u003cmeta charset=\"utf-8\"\u003e 58.2 mA\u003c\/p\u003e\n\n\u003cp\u003e \u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n\n\u003cli\u003e \u003cspan\u003e\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e Standard. Tested and approved for use in hi-fi and guitar amplifiers.\u003c\/span\u003e\n\u003c\/li\u003e\n\n \u003cli\u003e\u003cspan\u003e\u003cstrong\u003eOutput Quality:\u003c\/strong\u003e Excellent – ​​Very strong and stable output, no fluctuations.\u003c\/span\u003e\u003c\/li\u003e\n\n\u003cli\u003e \u003cspan\u003e\u003cstrong\u003eShort circuits and GAS:\u003c\/strong\u003e Absent.\u003c\/span\u003e\n\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch3\u003e \u003cstrong\u003eConditions:\u003c\/strong\u003e\n\u003c\/h3\u003e\n\n\u003cul\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eCondition:\u003c\/strong\u003e \u003cspan\u003eVintage tubes - tested with emission results consistent with NOS condition; pins in perfect condition. Supplied in our custom box for optimal protection.\u003c\/span\u003e\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eFunctionality:\u003c\/strong\u003e Fully functional.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eCosmetic condition:\u003c\/strong\u003e \u003cspan\u003eGood – Some lettering is eroded. Valve body in good condition. See photos for details.\u003c\/span\u003e\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eManufacturing Code:\u003c\/strong\u003e \u003cspan\u003eSame manufacturing code, unreadable, MO Valve Co. Ltd. production, identifiable by construction features. 1950s\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n \u003cp\u003e\u003ca rel=\"noopener\" title=\"Why our tubes are different – ​​the VTT protocol that improves sound, reliability and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"MO Valve Co. Ltd.; GB","offers":[{"title":"Default Title","offer_id":47897758663004,"sku":"03397-ONSPEC","price":499.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/2_847c67c1-3615-442a-8f46-8d3e4d77d717.jpg?v=1769711499"},{"product_id":"6v6-gt-tung-sol-black-glass-getter-tested-tube-made-in-usa","title":"6V6 GT DELCO by TUNG-SOL Black Glass Square Getter Tested Tube MADE IN USA '51","description":"\u003cp class=\"p1\"\u003e\u003cstrong\u003e6V6GT DELCO by TUNG-SOL Black Glass Square Getter Tested Tube MADE IN USA '51 AMPLITREX Tested Tube\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cb\u003eGeneral Description\u003c\/b\u003e\u003c\/h3\u003e\n\u003cp class=\"p3\"\u003eThe \u003cspan class=\"s2\"\u003e\u003cb\u003e1951 6V6GT DELCO by TUNG-SOL Black Glass\u003c\/b\u003e\u003c\/span\u003e represents one of the most authentic expressions of American post-war production. Manufactured by \u003cspan class=\"s2\"\u003e\u003cb\u003eTung-Sol for DELCO\u003c\/b\u003e\u003c\/span\u003e, this tube combines high industrial quality with a construction typical of the most sought-after series, featuring \u003cspan class=\"s2\"\u003e\u003cb\u003eBlack Glass\u003c\/b\u003e\u003c\/span\u003e and \u003cspan class=\"s2\"\u003e\u003cb\u003eSquare Getter\u003c\/b\u003e\u003c\/span\u003e, distinguishing elements of the finest productions of that era.\u003c\/p\u003e\n\u003cp class=\"p3\"\u003eThe black glass is not just an aesthetic choice; it contributes to better emission management and more stable performance over time. The \u003cspan class=\"s2\"\u003e\u003cb\u003emanufacturing code 322 112\u003c\/b\u003e\u003c\/span\u003e confirms Tung-Sol production, synonymous with reliability and manufacturing consistency.\u003c\/p\u003e\n\u003cp class=\"p3\"\u003eThis is a \u003cspan class=\"s2\"\u003e\u003cb\u003eused but selected and tested tube\u003c\/b\u003e\u003c\/span\u003e, which fully retains the charm and musicality of 1950s American 6V6s.\u003c\/p\u003e\n\u003cp class=\"p3\"\u003eTested with \u003cspan class=\"s2\"\u003e\u003cb\u003eAmplitrex AT-1000\u003c\/b\u003e\u003c\/span\u003e, it delivered a \u003cspan class=\"s2\"\u003e\u003cb\u003eSTRONG\u003c\/b\u003e\u003c\/span\u003e result, confirming excellent operational performance.\u003c\/p\u003e\n\u003ch3\u003e\u003cb\u003eSound Characteristics\u003c\/b\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eBass\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"p3\"\u003eWarm and round, with a rich texture typical of the best Tung-Sol productions. Never overwhelming, but always well-articulated.\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eMidrange\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p3\"\u003eRich and engaging, with a natural harmonic texture. Voices emerge with realism and depth.\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eTreble\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p3\"\u003eSweet and refined, never aggressive. They offer detail without fatigue, maintaining fluid musicality.\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eDynamics\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p3\"\u003eProgressive and musical, with an organic response that enhances the naturalness of the signal.\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eSoundstage\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p3\"\u003eWide and three-dimensional, with good separation and credible instrument placement.\u003c\/p\u003e\n\u003ch3\u003e\u003cb\u003e🎧 Use in Hi-Fi Amplifiers\u003c\/b\u003e\u003c\/h3\u003e\n\u003cp class=\"p3\"\u003eThis 6V6GT is ideal for systems where a \u003cspan class=\"s2\"\u003e\u003cb\u003ewarm, musical, and engaging sound\u003c\/b\u003e\u003c\/span\u003e, typical of 1950s American tubes, is desired.\u003c\/p\u003e\n\u003cp class=\"p3\"\u003eParticularly suitable for:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"p1\"\u003esingle-ended amplifiers\u003c\/li\u003e\n\u003cli class=\"p1\"\u003evintage configurations\u003c\/li\u003e\n\u003cli class=\"p1\"\u003esystems oriented towards musicality rather than pure analytical precision\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cb\u003e🎸 Use in Musical Applications\u003c\/b\u003e\u003c\/h3\u003e\n\u003cp class=\"p3\"\u003eIn guitar applications, it offers:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"p1\"\u003esoft and progressive breakup\u003c\/li\u003e\n\u003cli class=\"p1\"\u003egreat expressiveness in the mids\u003c\/li\u003e\n\u003cli class=\"p1\"\u003enatural dynamic response\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"p3\"\u003ePerfect for those seeking the classic \"vintage American tone.\"\u003c\/p\u003e\n\u003ch3\u003e\u003cb\u003e🎯 Note for audiophiles and technicians\u003c\/b\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli class=\"p1\"\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eManufacturer:\u003c\/b\u003e\u003c\/span\u003e Tung-Sol (DELCO branded)\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eYear:\u003c\/b\u003e\u003c\/span\u003e 1951\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eConstruction:\u003c\/b\u003e\u003c\/span\u003e Black Glass – Square Getter\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cb\u003eFactory code:\u003c\/b\u003e\u003cspan class=\"s1\"\u003e 322 112\u003c\/span\u003e\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eTest:\u003c\/b\u003e\u003c\/span\u003e AMPLITREX AT-1000\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"p3\"\u003eA tube with strong historical and sonic character, capable of offering an \u003cspan class=\"s2\"\u003e\u003cb\u003eauthentically American voice\u003c\/b\u003e\u003c\/span\u003e, ideal for those who desire a warm, natural sound rich in personality.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eTube tested on\u003cspan\u003e\u0026nbsp;\u003c\/span\u003e\u003cstrong\u003eAMPLITREX AT-1000\u003cspan\u003e\u0026nbsp;\u003c\/span\u003e\u003c\/strong\u003eTube Tester:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eTest Conditions:\u003c\/strong\u003e\u003cspan\u003e\u0026nbsp;Va = 250V; Vg2 = 250V; Vg = -12.5V\u0026nbsp;\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eMeasurements taken after 10 minutes of warm-up.\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eAverage 100%:\u003c\/strong\u003e\u003cspan\u003e\u0026nbsp;Gm = 4.1 ; Ia = 45 mA\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eTest Result:\u003c\/strong\u003e\u0026nbsp;STRONG\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eTube :\u003c\/strong\u003e\u003cspan\u003e\u0026nbsp;\u003c\/span\u003e\u003cspan\u003eGm = 4.1 ; Ia = 37 mA\u003c\/span\u003e\u003c\/p\u003e\n\u003cdiv\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/div\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eMicrophonics:\u0026nbsp;\u003c\/strong\u003eLow. Tested and suitable for use in hi-fi, including phono stages and guitar amplifiers.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eEmission Quality:\u003c\/strong\u003e\u0026nbsp;Excellent – Strong and stable emission, without fluctuations.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eShort Circuits and GAS:\u003c\/strong\u003e\u0026nbsp;Absent.\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eCondition:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli data-start=\"221\" data-end=\"371\"\u003e\u003cstrong data-start=\"223\" data-end=\"233\"\u003eCondition:\u003c\/strong\u003e\u003cspan\u003e\u0026nbsp;\u003c\/span\u003eVintage Tubes - Tested and fully functional. Supplied in our custom box for optimal protection.\u0026nbsp;\u003c\/li\u003e\n\u003cli data-start=\"372\" data-end=\"456\"\u003e\u003cstrong data-start=\"374\" data-end=\"391\"\u003eFunctionality:\u003c\/strong\u003e\u003cspan\u003e\u0026nbsp;\u003c\/span\u003eFully operational, with excellent test results.\u003c\/li\u003e\n\u003cli data-start=\"457\" data-end=\"672\"\u003e\u003cstrong data-start=\"459\" data-end=\"484\"\u003eCosmetic condition:\u003c\/strong\u003e\u003cspan\u003e \u003cmeta charset=\"utf-8\"\u003eVery Good – lettering clearly legible. There is a \u003cspan class=\"s2\"\u003e\u003cb\u003esmall crack on the plastic base\u003c\/b\u003e\u003c\/span\u003e, visible in the photos. This is an exclusively aesthetic defect that \u003cspan class=\"s2\"\u003e\u003cb\u003edoes not affect functionality\u003c\/b\u003e\u003c\/span\u003e, as confirmed by tests.\u003c\/span\u003e\u003cstrong data-start=\"675\" data-end=\"703\"\u003e\u003c\/strong\u003e See photos for details.\u003c\/li\u003e\n\u003cli data-start=\"457\" data-end=\"672\"\u003e\u003cstrong data-start=\"675\" data-end=\"703\" style=\"font-family: -apple-system, BlinkMacSystemFont, 'San Francisco', 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif; font-size: 0.875rem;\"\u003eManufacturing code:\u003c\/strong\u003e\u003cspan style=\"font-family: -apple-system, BlinkMacSystemFont, 'San Francisco', 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif; font-size: 0.875rem;\"\u003e 322 112 - 322 → Tung-Sol Electric Inc., Newark 4, N. J. - 112 → RMA\/EIA Open Date Code → manufactured in the 12th week of 1951\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003e \u003ca href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" title=\"Perché le nostre valvole sono diverse – il protocollo VTT che migliora suono, affidabilità e durata\" rel=\"noopener\" target=\"_blank\"\u003e\u003cstrong\u003eDiscover why our tubes are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/span\u003e\u003c\/p\u003e","brand":"TUNG-SOL","offers":[{"title":"Default Title","offer_id":48007042695516,"sku":"02139","price":69.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/3_46cc560c-21d9-4652-b365-28f33d141ee4.jpg?v=1713272411"},{"product_id":"6bq5-el84-ge-gray-plates-halo-getter-matched-tubes-made-in-usa-1","title":"6BQ5 ( EL84 ) GE Gray Plates Halo Getter Matched Tubes Made in USA","description":"\u003cp\u003e\u003cstrong\u003e6BQ5 ( EL84 ) GE Gray Plates Halo Getter Matched Tubes\u003c\/strong\u003e\u003cbr\u003e\u003cstrong\u003eMADE IN USA '60s\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eProduced by General Electric U.S.A.\u003cbr\u003eLogos worn as per photo\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIn our personalized white box\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe GE 6BQ5 \/ EL84 are very high quality, extremely reliable valves. They provide a balanced presentation and a \"meaty\" sound. They are quite responsive valves.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eTested on AMPLITREX AT-1000 Tube tester:\u003c\/strong\u003e\u003cbr\u003eVoltage Test: Va = 250V, Vg2 = 250V, Vg1 = -7.3V\u003cbr\u003eAverage 100% Gm = 11.3; Ia = 48 mA\u003cbr\u003e\u003cstrong\u003eTEST RESULT: VERY STRONG\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eValve 1: Gm 10.7 ; Ia = 44 mA\u003cbr\u003eValve 2: Gm 10.6; Ia = 43 mA\u003c\/p\u003e\n\u003cp\u003eFurther tests performed:\u003cbr\u003eMicrophony Test\u003cbr\u003eEmission Quality\u003cbr\u003eShort Circuit Test\u003cbr\u003eGAS Test\u003c\/p\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca rel=\"noopener\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"GE","offers":[{"title":"Default Title","offer_id":48052063109468,"sku":"02151X","price":129.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/2_b3e1996d-640f-467a-adb9-9ba9fa8b2b92.jpg?v=1781602909"},{"product_id":"6l6-gb-motorola-nos-nib-gray-plates-dd-getter-matched-pair-tubes-made-in-usa","title":"6L6 GB Motorola NOS NIB by RCA – Gray Plates DD Getter – Matched Pair USA Tubes","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cstrong\u003e6L6GB MOTOROLA NOS NIB by RCA Gray Plates DD Getter Matched Pair Tubes MADE IN USA\u003c\/strong\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eTubes produced by RCA USA for Motorola\u003c\/strong\u003e\u0026nbsp;\u003c\/p\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003eThe white dot on the base indicates that they were selected for Low Noise \u0026amp; Microphonics by the manufacturer.\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eTested with AMPLITREX AT-1000 Tube tester:\u003c\/strong\u003e\u003cbr\u003eOur instruments are calibrated with reference tubes.\u003cbr\u003eVf = 6.3V; Va = 350; Vg2 = 250; Vg = -18V\u003cbr\u003eAverage 100% Gm = 5200 ; Ia = 54 mA\u003cbr\u003e\u003cstrong\u003eTEST RESULT:\u003c\/strong\u003e\u003c\/span\u003e \u003cstrong\u003eVERY STRONG\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eValve 1: Gm = 4600 ; Ia = 59 mA\u003cbr\u003eValve 2: Gm = 5100 ; Ia = 57 mA\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eFurther tests performed:\u003cbr\u003eMicrophone Test\u003cbr\u003eEmission Quality\u003cbr\u003eShort Circuit Test\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003eGAS Test\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca rel=\"noopener\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/span\u003e\u003c\/p\u003e","brand":"MOTOROLA","offers":[{"title":"Default Title","offer_id":49187926835548,"sku":"02377","price":219.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_e15d531e-4948-41d0-80b6-f6c8a3279845.jpg?v=1723538220"},{"product_id":"6bq5-el84-rca-nos-nib-gray-plates-matched-pair-tubes-made-in-usa-63","title":"6BQ5 ( EL84 ) RCA NOS NIB Gray Plates Disc Halo Getter Matched Pair Tubes Made in USA '63","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cspan\u003e\u003cstrong\u003e6BQ5 ( EL84 ) RCA NOS NIB Gray Plates Disc Halo Getter Matched Pair Tubes MADE IN USA '63\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eProduced by RCA in the U.S.A.\u003cbr\u003eLogos worn as per photo\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003eThese tubes have been carefully selected to ensure maximum coherence and audio performance. Ideal for enthusiasts looking to improve the sound quality of their amplifiers. EL84 RCA Gray Plates are renowned for their ability to deliver warm, detailed tones while maintaining a balanced and precise response. Each pair has been precisely tested and matched to ensure maximum compatibility and optimal performance. This perfect pairing allows for a balanced and synchronized sound performance, elevating the listening experience to a higher level. Perfect for any vintage or modern amp. These tubes are becoming increasingly rare.\u003cbr\u003e\u003cbr\u003e\u003c\/span\u003e\u003cspan\u003e\u003cstrong\u003eTested on AMPLITREX AT-1000 Tube tester:\u003c\/strong\u003e\u003cbr\u003eVoltage Test: Va = 250V, Vg2 = 250V, Vg1 = -7.3V\u003cbr\u003eAverage 100% Gm = 11.3 ; Ia = 48 mA\u003cbr\u003e\u003cstrong\u003eTEST RESULT: VERY STRONG\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eValve 1: Gm 11.0 ; Ia = 44 mA\u003cbr\u003eValve 2: Gm 9.6; Ia = 44 mA\u003cbr\u003e\u003cbr\u003e\u003c\/span\u003e\u003cspan\u003eFurther tests performed:\u003cbr\u003eMicrophony Test\u003cbr\u003eEmission Quality\u003cbr\u003eShort Circuit Test\u003cbr\u003eGAS Test\u003c\/span\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca rel=\"noopener\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"RCA","offers":[{"title":"Default Title","offer_id":49238659400028,"sku":"02380","price":84.9,"currency_code":"EUR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/2_a7d574b7-94c0-41ef-9894-2665eb1188ef.jpg?v=1724234271"},{"product_id":"6bq5-el84-rca-nos-nib-gray-plates-disc-halo-getter-tested-pair-tubes-made-in-usa-66","title":"6BQ5 ( EL84 ) RCA NOS NIB Gray Plates Disc Halo Getter Tested Pair Tubes Made in USA '66","description":"\u003cp\u003e\u003cstrong\u003e6BQ5 ( EL84 ) RCA NOS NIB Gray Plates Disc Halo Getter Tested Pair Tubes\u003c\/strong\u003e\u003cbr\u003e\u003cstrong\u003eMade in USA '66\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eProduced by RCA in the U.S.A.\u003cbr\u003eLogos worn as per photo\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eEL84 RCA Gray Plates are renowned for their ability to deliver warm, detailed tones while maintaining a balanced and precise response. \u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eExcellent for any vintage or modern amplifier with single tube Bias adjustment or using a single 6BQ5 (EL84) for each channel.\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eThis pair is not suitable for Push-Pull amplifiers.\u003c\/strong\u003e\u003cbr\u003e\u003cbr\u003e\u003c\/span\u003e\u003cspan\u003e\u003cstrong\u003eTested on AMPLITREX AT-1000 Tube tester:\u003c\/strong\u003e \u003cbr\u003eVoltage Test: Va = 250V, Vg2 = 250V, Vg1 = -7.3V\u003cbr\u003eAverage 100% Gm = 11.3 ; Ia = 48 mA\u003cbr\u003e\u003cstrong\u003eTEST RESULT: VERY STRONG\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eValve 1: Gm 11.4 ; Ia = 58 mA\u003cbr\u003eValve 2: Gm 10.3; Ia = 36 mA\u003cbr\u003e\u003cbr\u003e\u003c\/span\u003e\u003cspan\u003eFurther tests performed:\u003cbr\u003eMicrophony Test\u003cbr\u003eEmission Quality\u003cbr\u003eShort Circuit Test\u003cbr\u003eGAS Test\u003c\/span\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca rel=\"noopener\" title=\"Perché le nostre valvole sono diverse – il protocollo VTT che migliora suono, affidabilità e durata\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eScopra perché le nostre valvole sono diverse →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/span\u003e\u003c\/p\u003e","brand":"RCA","offers":[{"title":"Default Title","offer_id":49238792700252,"sku":"02381","price":69.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/3_17794b9d-c9b2-4961-8a1a-64ed61ee3a84.jpg?v=1724236695"},{"product_id":"6bq5-el84-amperex-philips-heerlen-plant-gray-plates-halo-getter-rx3-matched-tubes-made-in-holland","title":"6BQ5 ( EL84 ) PHILIPS Gray Plates Halo Getter rX3 Matched Tubes Made in AUSTRIA '50s","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cstrong\u003e6BQ5 ( EL84 ) PHILIPS Gray Plates Halo Getter rX3 Matched Tubes\u003c\/strong\u003e\u003cbr\u003e\u003cstrong\u003eMADE IN AUSTRIA in the 1950s\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eProduced by PHILIPS for Hammond Organ.\u003c\/strong\u003e\u003cbr\u003eLogos worn as per photo\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003eSame manufacturing code\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003e- Guaranteed Used -\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eManufacture Codes:\u0026nbsp;\u003c\/strong\u003e\u003c\/span\u003e\u003cbr\u003erX3 A93 = 1959\u003cbr\u003e\u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003erX3 A93 \u003cmeta charset=\"utf-8\"\u003e= \u003cmeta charset=\"utf-8\"\u003e1959\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eTested on AMPLITREX AT-1000 Tube tester:\u003c\/strong\u003e\u003cbr\u003eVoltage Test: Va = 250V, Vg2 = 250V, Vg1 = -7,3V\u003cbr\u003eAverage 100% Gm = 11 ,3 ; Ia = 48 mA\u003cbr\u003e\u003cstrong\u003eTEST RESULT: VERY STRONG\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eValve 1: Gm 9.9; Ia = 41 mA\u003cbr\u003eValve 2: Gm 9.0 ; Ia = 40 mA\u003cbr\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eFurther tests performed:\u003cbr\u003eMicrophony Test\u003cbr\u003eEmission Quality\u003cbr\u003eTest for Short Circuits\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003eTest for GAS\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca rel=\"noopener\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/span\u003e\u003c\/p\u003e","brand":"PHILIPS","offers":[{"title":"Default Title","offer_id":49242973798748,"sku":"02384","price":59.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/3_4097ca56-e724-4667-853c-b5f0722f8f9c.jpg?v=1724319635"},{"product_id":"6ca7-el34-amperex-nos-nib-by-mullard-xf3-halo-getter-matched-tubes-made-in-gt-britain","title":"6CA7 \/ EL34 Amperex by MULLARD Blackburn XF3 – NOS NIB Halo Getter - Two Matched Pairs - Made in Great Britain","description":"\u003cp class=\"p1\"\u003e\u003cb\u003e6CA7 \/ EL34 Mullard XF3 – Amperex Label – Two Matched Pairs – NOS NIB – Halo Getter – Made in Great Britain\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e\u003cb\u003eAMPLITREX Tested – TWO HIGH-GRADE MATCHED PAIRS – VERY STRONG – Original Amperex Boxes\u003c\/b\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eDescription\u003c\/b\u003e\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp class=\"p3\"\u003eSet consisting of \u003cspan class=\"s1\"\u003e\u003cb\u003efour 6CA7 \/ EL34 Mullard XF3 NOS NIB\u003c\/b\u003e\u003c\/span\u003e, Amperex branded and produced in the historic Mullard factory in \u003cspan class=\"s1\"\u003e\u003cb\u003eBlackburn, Great Britain\u003c\/b\u003e\u003c\/span\u003e, carefully selected as \u003cspan class=\"s1\"\u003e\u003cb\u003etwo distinct high-grade matched pairs\u003c\/b\u003e\u003c\/span\u003e.\u003c\/p\u003e\n\u003cp class=\"p3\"\u003eThis is not a single matched quartet of four tubes, but \u003cspan class=\"s1\"\u003e\u003cb\u003etwo electrically coherent pairs\u003c\/b\u003e\u003c\/span\u003e, each selected for anode current and transconductance. This configuration is particularly interesting for dual mono amplifiers, mono power amplifiers, systems using two separate pairs, or for those who wish to have a second perfectly selected Mullard XF3 pair.\u003c\/p\u003e\n\u003cp class=\"p3\"\u003eThe tubes are in \u003cspan class=\"s1\"\u003e\u003cb\u003eNOS NIB – New Old Stock, New In Box\u003c\/b\u003e\u003c\/span\u003e condition, supplied in their original Amperex boxes. The construction features a Halo Getter and the typical characteristics of Mullard XF3 production from the 1970s, highly sought after today for build quality, operational stability, and authentic British sound character.\u003c\/p\u003e\n\u003cp class=\"p3\"\u003eAll four tubes have been tested in our laboratory using the \u003cspan class=\"s1\"\u003e\u003cb\u003eAmplitrex AT-1000 Tube Tester\u003c\/b\u003e\u003c\/span\u003e. Both pairs received a \u003cspan class=\"s1\"\u003e\u003cb\u003eVERY STRONG\u003c\/b\u003e\u003c\/span\u003e rating, with stable emission, absence of shorts and gas, and very solid electrical values.\u003c\/p\u003e\n\u003cp class=\"p3\"\u003eSonically, they offer the classic Mullard character: deep and controlled bass, rich, natural, and three-dimensional mids, smooth and never aggressive highs. The presentation is expansive, harmonically complete, and musically engaging, with excellent dynamics and great tonal naturalness.\u003c\/p\u003e\n\u003cp class=\"p3\"\u003eSuitable for high-end hi-fi amplifiers, push-pull power amplifiers, dual mono configurations, vintage restorations, and guitar amplifiers compatible with \u003cspan class=\"s1\"\u003e\u003cb\u003eEL34 \/ 6CA7\u003c\/b\u003e\u003c\/span\u003e.\u003c\/p\u003e\n\u003cp class=\"p3\"\u003eA rare set consisting of \u003cspan class=\"s1\"\u003e\u003cb\u003etwo matched Mullard XF3 \/ Amperex Label NOS NIB pairs\u003c\/b\u003e\u003c\/span\u003e, genuinely tested and selected by Vacuum Tubes Treasures, ideal for those seeking four original British EL34s without compromising electrical coherence within each pair.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eTube tested on \u003cstrong\u003eAMPLITREX AT-1000 \u003c\/strong\u003eTube Tester:\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eTest Conditions:\u003c\/strong\u003e\u003cspan\u003e Va = 450V; Vg2 = 360; Vg = -30V\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eAverage 100%:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eGm = 4.4 ; Ia = 40 mA\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eTest Result:\u003c\/strong\u003e VERY STRONG\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cstrong\u003eTube 1:\u003c\/strong\u003e Gm = 7.5 ; Ia = 56 mA\u003c\/p\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cstrong\u003eTube 2:\u003c\/strong\u003e Gm = 7.7 ; Ia = 54 mA\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eTube 3:\u003c\/strong\u003e Gm = 6.6 ; Ia = 40 mA\u003c\/p\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cstrong\u003eTube 4:\u003c\/strong\u003e Gm = 6.5 ; Ia = 37 mA\u003c\/p\u003e\n\u003cdiv\u003e\u003cstrong\u003eAdditional tests performed:\u003c\/strong\u003e\u003c\/div\u003e\n\u003cul\u003e\n\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e \u003cmeta charset=\"utf-8\"\u003eStandard. Tested and suitable for use in hi-fi and guitar amplifiers.\u003c\/span\u003e\u003c\/li\u003e\n\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eEmission Quality:\u003c\/strong\u003e Excellent – Very strong and stable emission, without fluctuations.\u003c\/span\u003e\u003c\/li\u003e\n\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eShorts and GAS:\u003c\/strong\u003e Absent.\u003c\/span\u003e\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eConditions:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eCondition:\u003c\/strong\u003e NOS - NIB - New Old Stock, New In Box - Tested and working - In original box.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eFunctionality: \u003c\/strong\u003ePerfectly operational.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eCosmetic Condition:\u003c\/strong\u003e Excellent – Markings perfectly preserved, minimal signs of wear. See photos.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\n\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eManufacturing Code: \u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003eXf3 \u003cmeta charset=\"utf-8\"\u003eB5C5 produced at Mullard's Blackburn (UK) plant in March 1975\u003c\/li\u003e\n\n\u003cli\u003eXf3 B5H3 produced at Mullard's Blackburn (UK) plant in August 1975\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca rel=\"noopener\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eDiscover why our tubes are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"AMPEREX","offers":[{"title":"Default Title","offer_id":49301921562972,"sku":"02401M","price":1390.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/4_aeb20892-28aa-4450-9e7f-9c4fdf519101.jpg?v=1725299000"},{"product_id":"2a3-vt-95-rca-bi-plates-black-plates-dual-bottom-getter-matched-tubes-made-in-usa-50s-copy","title":"12B4A GE NOS Black Plates Halo Getter Low Noise \u0026amp; Microphonic Matched Pair Tubes Made in USA","description":"\u003cp\u003e\u003cstrong\u003e12B4A GE NOS Black Plates Halo Getter Low Noise \u0026amp; Microphonic Matched Pair Tubes\u003c\/strong\u003e\u003cbr\u003e\u003cstrong\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eMade in USA\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eLow Noise \u0026amp; Microphonics\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eWorn logos as per photo\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIn Box Aftermarket\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eTested on AMPLITREX AT-1000 Tube tester:\u003c\/strong\u003e\u003cbr\u003eVoltage Test: Va = 150V, Vg = -17.5V\u003cbr\u003eAVERAGE 100% Gm = 6.4 ; Ia = 34 mA\u003cbr\u003e\u003cstrong\u003eTEST RESULT: VERY STRONG\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eValve 1: Gm = 6.0 ; Ia = 33 mA\u003cbr\u003eValve 2: Gm = 6.1 ; Ia = 34 mA\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eFurther tests performed:\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003eMicrophone Test\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003eEmission Quality\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003eShort Circuit Test\u003c\/span\u003e\u003cbr\u003eGAS Test\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca rel=\"noopener\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/span\u003e\u003c\/p\u003e","brand":"GE","offers":[{"title":"Default Title","offer_id":49383587414364,"sku":"02417M","price":24.9,"currency_code":"EUR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_94917072-a098-403e-9111-b7721d2fc8e8.jpg?v=1726650179"},{"product_id":"6v6-gt-zenith-black-glass-chrome-top-tested-tube-made-in-usa-53-copia","title":"6V6GT Zenith – Black Glass Chrome Top Tested Tube USA 1953","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cstrong\u003e6V6 GT ZENITH Black Glass CHROME TOP Tested Tube\u003c\/strong\u003e\u003cbr\u003e \u003cstrong\u003eMade in USA '53\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e \u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e These tubes are particularly appreciated for their warm, enveloping sound, ideal for use in guitar amplifiers. Thanks to their Black Glass design and Chrome Top construction, they offer a unique tone that is perfect for those seeking an authentic vintage sound.\u003c\/p\u003e\n\u003cp\u003e The low end is rounded and well-defined, with deep, controlled bass that adds a solid foundation to the overall tone. This makes the 6V6 GT ZENITH ideal for guitarists who want a punchy low-end response, perfect for genres like blues, classic rock, and country. The low end remains tight and focused, providing clarity that doesn't overwhelm other frequencies.\u003c\/p\u003e\n\u003cp\u003e The midrange, a strong point of these tubes, is rich and full, with a smoothness that makes the guitar sound fluid and musical. The midrange is ideal for emphasizing the tones of the guitar's middle register, making it perfect for both warm and powerful rhythms and expressive solos. The touch response is dynamic and responsive, offering a wide range of sonic nuances.\u003c\/p\u003e\n\u003cp\u003e The high frequencies are well-balanced, sweet but never harsh, making these tubes perfect for achieving natural and pleasant harmonic saturation. The Chrome Top design helps maintain a balanced brightness in the high frequencies, preventing the sound from becoming fatiguing even at high volumes or with higher gain. This feature is particularly appreciated in guitar amplifiers, where clarity of sound is crucial.\u003c\/p\u003e\n\u003cp\u003e Overall, the 1953 6V6 GT ZENITH with Black Glass and Chrome Top delivers a warm, classic tone with exceptional dynamics and precise attack response, making them an excellent choice for guitarists who want a rich, detailed, vintage sound.\u003c\/p\u003e\n\u003cp\u003e \u003cspan style=\"font-family: -apple-system, BlinkMacSystemFont, 'San Francisco', 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif; font-size: 0.875rem;\"\u003eProduction SYLVANIA USA for Zenith\u003cmeta charset=\"utf-8\"\u003e USA\u003c\/span\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003e \u003cstrong\u003eTested with AMPLITREX AT-1000 Tube Tester:\u003c\/strong\u003e\u003cbr\u003e \u003cspan\u003eOur instruments are calibrated with reference tubes.\u003c\/span\u003e\u003cbr\u003e \u003cspan\u003eVf = 6.3V; Va = 250V; Vg2 = 250V; Vg = -12.5V\u003c\/span\u003e\u003cbr\u003e \u003cspan\u003eAverage 100% Gm = 4.1 ; Ia = 45 mA\u003c\/span\u003e\u003cbr\u003e \u003cstrong\u003eTEST RESULT: STRONG\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e \u003cspan\u003eGm = 3.2 ; Ia = 39 mA\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e \u003cspan\u003eFurther tests performed:\u003c\/span\u003e\u003cbr\u003e \u003cspan\u003eMicrophone Test\u003c\/span\u003e\u003cbr\u003e \u003cspan\u003eEmission Quality\u003c\/span\u003e\u003cbr\u003e \u003cspan\u003eShort Circuit Test\u003c\/span\u003e\u003cbr\u003e GAS Test\u003cspan\u003e\u003c\/span\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e \u003ca rel=\"noopener\" title=\"Why our tubes are different – ​​the VTT protocol that improves sound, reliability and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"SYLVANIA","offers":[{"title":"Default Title","offer_id":49498081034588,"sku":"02479","price":34.9,"currency_code":"EUR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_518c3199-4fc6-4d7c-ae19-edccd46b1b0e.jpg?v=1728288313"},{"product_id":"6v6-gt-tung-sol-nos-nib-black-glass-square-getter-matched-tubes-made-in-usa-55","title":"6V6GT NOS NIB TUNG-SOL Black Glass Matched Pair Tubes Square Getter Same Codes Made in USA '55","description":"\u003cp class=\"p1\"\u003e\u003cb\u003e6V6GT NOS NIB TUNG-SOL – Black Glass – Matched Pair – Square Getter – Same Codes – Made in USA 1955\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e\u003cb\u003eAMPLITREX Tested – VERY STRONG\u003c\/b\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cb\u003eGeneral Description\u003c\/b\u003e\u003c\/h3\u003e\n\u003cp class=\"p4\"\u003eThis \u003cspan class=\"s2\"\u003e\u003cb\u003ematched pair of 6V6GT NOS NIB Tung-Sol\u003c\/b\u003e\u003c\/span\u003e tubes, manufactured in the USA in \u003cspan class=\"s2\"\u003e\u003cb\u003e1955\u003c\/b\u003e\u003c\/span\u003e, represents one of the most iconic and sought-after versions of the American 6V6 family.\u003c\/p\u003e\n\u003cp class=\"p4\"\u003eThe tubes feature the famous construction:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"p1\"\u003e\u003cb\u003eBlack Glass\u003c\/b\u003e\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cb\u003eSquare Getter\u003c\/b\u003e\u003c\/li\u003e\n\u003cli class=\"p1\"\u003etypical Tung-Sol internal structure from the 1950s\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"p4\"\u003e\u003cspan class=\"s2\"\u003e\u003cb\u003eBlack glass\u003c\/b\u003e\u003c\/span\u003e is particularly appreciated for the quality of its materials and its distinctive sonic character, while the \u003cspan class=\"s2\"\u003e\u003cb\u003esquare getter\u003c\/b\u003e\u003c\/span\u003e identifies an early production, which is increasingly rare today.\u003c\/p\u003e\n\u003cp class=\"p4\"\u003eBoth tubes bear \u003cspan class=\"s2\"\u003e\u003cb\u003ethe same manufacturing code 322550-3\u003c\/b\u003e\u003c\/span\u003e, confirming their origin from the same production batch.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e\u003cspan class=\"s3\"\u003eThe pair is \u003c\/span\u003e\u003cb\u003eNOS NIB (New Old Stock – New In Box)\u003c\/b\u003e\u003cspan class=\"s3\"\u003e and has been selected as a \u003c\/span\u003e\u003cb\u003eMatched Pair\u003c\/b\u003e\u003cspan class=\"s3\"\u003e.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"p4\"\u003e⚠️ One tube has a \u003cspan class=\"s2\"\u003e\u003cb\u003esmall crack on the plastic base\u003c\/b\u003e\u003c\/span\u003e, as shown in the photos. This is a purely cosmetic defect that \u003cspan class=\"s2\"\u003e\u003cb\u003edoes not affect functionality\u003c\/b\u003e\u003c\/span\u003e, as confirmed by tests.\u003c\/p\u003e\n\u003ch3\u003e\u003cb\u003eSonic Characteristics\u003c\/b\u003e\u003c\/h3\u003e\n\u003cp class=\"p4\"\u003eThe \u003cspan class=\"s2\"\u003e\u003cb\u003eTung-Sol 6V6GT Black Glass from the 1950s\u003c\/b\u003e\u003c\/span\u003e are considered among the best in terms of musicality and character.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e\u003cb\u003eBass\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p4\"\u003eDeep and well-structured, with excellent control and natural presence.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e\u003cb\u003eMids\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p4\"\u003eRich, warm, and three-dimensional. Vocals sound extremely natural and engaging.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e\u003cb\u003eHighs\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p4\"\u003eSweet and refined, with a soft texture that avoids any harshness.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e\u003cb\u003eDynamics\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p4\"\u003eFluid and progressive, with a very musical and natural response.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e\u003cb\u003eSoundstage\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p4\"\u003eWide and well-developed, with excellent depth and separation.\u003c\/p\u003e\n\u003ch3\u003e\u003cb\u003e🎧 Use in Hi-Fi Amplifiers\u003c\/b\u003e\u003c\/h3\u003e\n\u003cp class=\"p4\"\u003eIdeal for amplifiers based on:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp class=\"p1\"\u003e\u003cb\u003e6V6GT \/ 6V6G \/ 6V6GTY\u003c\/b\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"p4\"\u003eParticularly suitable for hi-fi systems seeking:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"p1\"\u003emusicality and naturalness\u003c\/li\u003e\n\u003cli class=\"p1\"\u003erich midrange\u003c\/li\u003e\n\u003cli class=\"p1\"\u003ewarm and engaging sound\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"p4\"\u003eMatching and electrical consistency ensure stable performance in push-pull circuits.\u003c\/p\u003e\n\u003ch3\u003e\u003cb\u003e🎸 Use in Musical Applications\u003c\/b\u003e\u003c\/h3\u003e\n\u003cp class=\"p4\"\u003eAlso highly valued in guitar amplifiers:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"p1\"\u003esoft and progressive breakup\u003c\/li\u003e\n\u003cli class=\"p1\"\u003ewarm and harmonically complex mids\u003c\/li\u003e\n\u003cli class=\"p1\"\u003every expressive dynamic response\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"p4\"\u003eA classic choice for those who desire an authentic vintage sound.\u003c\/p\u003e\n\u003ch3\u003e\u003cb\u003e🎯 Note for Audiophiles and Technicians\u003c\/b\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli class=\"p1\"\u003e\u003cb\u003eTung-Sol – Made in USA – 1955\u003c\/b\u003e\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cb\u003eBlack Glass – Square Getter\u003c\/b\u003e\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cb\u003eSame Factory Code: 322550-3\u003c\/b\u003e\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cb\u003eMatched Pair\u003c\/b\u003e\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cb\u003eNOS NIB – New Old Stock, New In Box\u003c\/b\u003e\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cb\u003eAMPLITREX Tested – VERY STRONG\u003c\/b\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"p4\"\u003eA valuable pair, combining \u003cspan class=\"s2\"\u003e\u003cb\u003erarity, build quality, and sonic performance\u003c\/b\u003e\u003c\/span\u003e, ideal for those seeking a \u003cspan class=\"s2\"\u003e\u003cb\u003ereference vintage 6V6GT\u003c\/b\u003e\u003c\/span\u003e, with the charm and musicality of 1950s American production.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eTube tested on \u003cstrong\u003eAMPLITREX AT-1000 \u003c\/strong\u003eTube Tester:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest Conditions:\u003c\/strong\u003e\u003cspan\u003e \u003cmeta charset=\"utf-8\"\u003eVa = 250V; Vg2 = 250V; Vg = -12.5V \u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eMeasurements taken after 10 minutes of warm-up.\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAverage 100%:\u003c\/strong\u003e\u003cspan\u003e \u003cmeta charset=\"utf-8\"\u003eGm = 4.1 ; Ia = 45 mA\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest Result:\u003c\/strong\u003e VERY STRONG\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cstrong\u003eTube 1:\u003c\/strong\u003e \u003cmeta charset=\"utf-8\"\u003e\u003cspan\u003eGm = 4.1 ; Ia = 43.0 mA\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cstrong\u003eTube 2:\u003c\/strong\u003e \u003cmeta charset=\"utf-8\"\u003e\u003cspan\u003eGm = 4.2 ; Ia = 43.0 mA\u003c\/span\u003e\u003cstrong\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cdiv\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/div\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eMicrophonics: \u003c\/strong\u003eLow. Tested and suitable for hi-fi use, even in phono stages and guitar amplifiers.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eEmission Quality:\u003c\/strong\u003e Excellent – Very strong and stable emission, without fluctuations.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eShorts and GAS:\u003c\/strong\u003e Absent.\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eConditions:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli data-start=\"221\" data-end=\"371\"\u003e\n\u003cstrong data-start=\"223\" data-end=\"233\"\u003eCondition:\u003c\/strong\u003e NOS - NIB - New Old Stock, New In Box - Tested and functional - Supplied in original box.\u003c\/li\u003e\n\u003cli data-start=\"372\" data-end=\"456\"\u003e\n\u003cstrong data-start=\"374\" data-end=\"391\"\u003eFunctionality:\u003c\/strong\u003e Fully operational, with excellent test results.\u003c\/li\u003e\n\u003cli data-start=\"457\" data-end=\"672\"\u003e\n\u003cstrong data-start=\"459\" data-end=\"484\"\u003eCosmetic Condition:\u003c\/strong\u003e Markings excellently preserved, \u003cmeta charset=\"utf-8\"\u003eOne tube has a \u003cspan class=\"s2\"\u003e\u003cb\u003esmall crack on the plastic base\u003c\/b\u003e\u003c\/span\u003e, as shown in the photos. This is a purely cosmetic defect that \u003cspan class=\"s2\"\u003e\u003cb\u003edoes not affect functionality\u003c\/b\u003e\u003c\/span\u003e, as confirmed by tests. See photos for details.\u003c\/li\u003e\n\u003cli data-start=\"673\" data-end=\"797\"\u003e\n\u003cstrong data-start=\"675\" data-end=\"703\"\u003eManufacturing Code: \u003c\/strong\u003e322550-3 \u003cmeta charset=\"utf-8\"\u003e- 322 \u003cmeta charset=\"utf-8\"\u003e→ Tung-Sol Electric Inc., Newark 4, N. J. - 550 → RMA\/EIA Open Date Code → manufactured in the 50th week of 1955\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca rel=\"noopener\" title=\"Perché le nostre valvole sono diverse – il protocollo VTT che migliora suono, affidabilità e durata\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eDiscover why our tubes are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"TUNG-SOL","offers":[{"title":"Default Title","offer_id":49515817533788,"sku":"02485","price":189.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_2eedafaa-deb0-4b8c-8adc-e2620c07155e.jpg?v=1728553267"},{"product_id":"6bq5-el84-sovtek-o-getter-matched-pair-vacuum-tubes-made-in-russia","title":"6BQ5 ( EL84 ) SOVTEK O Getter Matched Quad Vacuum Tubes NEW","description":"\u003cp\u003e\u003cstrong\u003e6BQ5 (EL84) SOVTEK O Getter Matched Vacuum Tubes MADE IN RUSSIA\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eMade in Russia\u003c\/strong\u003e, these 6BQ5 (EL84) SOVTEK tubes with O Getter are matched pair tubes, perfect for high-quality Hi-Fi applications and tube amplifiers. They deliver a powerful and detailed sound, especially suitable for musicians and discerning audiophiles.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eLow frequencies:\u003c\/strong\u003e Controlled and punchy, with well-defined bass that provides a solid and precise foundation.\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eMid frequencies:\u003c\/strong\u003e Articulate and transparent, ideal for enhancing instruments and vocals in a vivid and natural way.\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eHigh frequencies:\u003c\/strong\u003e Crystal-clear and detailed, never fatiguing, making every nuance perfectly audible.\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eOverall sound signature:\u003c\/strong\u003e These tubes offer an open and balanced soundstage, with great dynamic management and instrument separation.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eAdditional Information:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe Sovtek EL84 produces exemplary, warm, and soft distortion. An excellent choice for vintage amplifiers like the VOX AC-30 and similar models. Sovtek EL84s are used by Fender, Crate, and Peavey.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eNOTE:\u003c\/strong\u003e Due to the bulb diameter, these tubes are not suitable for:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eBadCat Model 2R\u003c\/li\u003e\n\u003cli\u003eMarshall DSL201\u003c\/li\u003e\n\u003cli\u003eMarshall DSL401\u003c\/li\u003e\n\u003cli\u003eVOX reissue AC15\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eTubes tested on \u003cstrong\u003eAmplitrex AT-1000 Tube tester\u003c\/strong\u003e:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eTest Conditions:\u003c\/strong\u003e Va = 250V, Vg = -7.3V\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eAverage 100% Gm = 11.3 ; Ia = 48 mA\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eTube 1:\u003c\/strong\u003e\u003cspan style=\"font-family: -apple-system, BlinkMacSystemFont, 'San Francisco', 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif; font-size: 0.875rem;\"\u003e\u0026nbsp;Gm = 10.9 ; Ia =\u0026nbsp;53 mA\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eTube 2:\u003c\/strong\u003e\u003cspan style=\"font-family: -apple-system, BlinkMacSystemFont, 'San Francisco', 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif; font-size: 0.875rem;\"\u003e\u0026nbsp;Gm = 11.3 ; Ia =\u0026nbsp;54 mA\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eMicrophony Test\u003c\/li\u003e\n\u003cli\u003eEmission Quality Test\u003c\/li\u003e\n\u003cli\u003eShort Circuit Test\u003c\/li\u003e\n\u003cli\u003eGAS Test\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eCondition:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eNew\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eManufacturing Code:\u003c\/strong\u003e Same code\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca rel=\"noopener\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"SOVTEK","offers":[{"title":"Default Title","offer_id":49605754257756,"sku":"02525","price":55.68,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_95ecafcd-9888-4bb6-a689-8233a94a922a.jpg?v=1729847693"},{"product_id":"6bq5-el84-sovtek-o-getter-matched-quad-vacuum-tubes-made-in-russia","title":"6BQ5 EL84 Sovtek – O Getter Matched Quad Vacuum Tubes Russia","description":"\u003cp\u003e\u003cstrong\u003e6BQ5 (EL84) SOVTEK O Getter Matched Quad Vacuum Tubes MADE IN RUSSIA\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eMade in Russia\u003c\/strong\u003e, these 6BQ5 (EL84) SOVTEK tubes with O Getter are matched quad tubes, perfect for high-quality Hi-Fi applications and tube amplifiers. They deliver a powerful and detailed sound, especially suitable for musicians and discerning audiophiles.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eLow frequencies:\u003c\/strong\u003e Controlled and punchy, with well-defined bass that provides a solid and precise foundation.\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eMid frequencies:\u003c\/strong\u003e Articulate and transparent, ideal for enhancing instruments and vocals in a vivid and natural way.\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eHigh frequencies:\u003c\/strong\u003e Crystal-clear and detailed, never fatiguing, making every nuance perfectly audible.\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eOverall sound signature:\u003c\/strong\u003e These tubes offer an open and balanced soundstage, with great dynamic management and instrument separation.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eAdditional Information:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe Sovtek EL84 produces exemplary, warm, and soft distortion. An excellent choice for vintage amplifiers like the VOX AC-30 and similar models. Sovtek EL84s are used by Fender, Crate, and Peavey.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eNOTE:\u003c\/strong\u003e Due to the bulb diameter, these tubes are not suitable for:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eBadCat Model 2R\u003c\/li\u003e\n\u003cli\u003eMarshall DSL201\u003c\/li\u003e\n\u003cli\u003eMarshall DSL401\u003c\/li\u003e\n\u003cli\u003eVOX reissue AC15\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eTubes tested on \u003cstrong\u003eAmplitrex AT-1000 Tube tester\u003c\/strong\u003e:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eTest Conditions:\u003c\/strong\u003e Va = 250V, Vg = -7.3V\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eAverage 100% Gm = 11.3 ; Ia = 48 mA\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eTube 1:\u003c\/strong\u003e\u003cspan style=\"font-family: -apple-system, BlinkMacSystemFont, 'San Francisco', 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif; font-size: 0.875rem;\"\u003e\u0026nbsp;Gm = 12.0 ; Ia = 52 mA\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eTube 2:\u003c\/strong\u003e\u003cspan style=\"font-family: -apple-system, BlinkMacSystemFont, 'San Francisco', 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif; font-size: 0.875rem;\"\u003e\u0026nbsp;Gm = 11.2 ; Ia = 51 mA\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eTube 3:\u003c\/strong\u003e\u003cspan style=\"font-family: -apple-system, BlinkMacSystemFont, 'San Francisco', 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif; font-size: 0.875rem;\"\u003e\u0026nbsp;Gm = 11.6 ; Ia = 50 mA\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eTube 4:\u003c\/strong\u003e\u003cspan style=\"font-family: -apple-system, BlinkMacSystemFont, 'San Francisco', 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif; font-size: 0.875rem;\"\u003e\u0026nbsp;Gm = 11.7 ; Ia = 50 mA\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eMicrophony Test\u003c\/li\u003e\n\u003cli\u003eEmission Quality Test\u003c\/li\u003e\n\u003cli\u003eShort Circuit Test\u003c\/li\u003e\n\u003cli\u003eGAS Test\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eCondition:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eNew\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eManufacturing Code:\u003c\/strong\u003e Same Code\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca rel=\"noopener\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"SOVTEK","offers":[{"title":"Default Title","offer_id":49607369883996,"sku":"02527","price":111.38,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_111fafe1-319b-4254-9d6e-ee79da72d5f5.jpg?v=1729866252"},{"product_id":"6bq5-el84-sovtek-o-getter-matched-quad-vacuum-tubes-made-in-russia-1","title":"6BQ5 EL84 Sovtek – O Getter Matched Quad Vacuum Tubes Russia","description":"\u003cp\u003e\u003cstrong\u003e6BQ5 (EL84) SOVTEK O Getter Matched Quad Vacuum Tubes MADE IN RUSSIA\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eMade in Russia\u003c\/strong\u003e, these 6BQ5 (EL84) SOVTEK tubes with O Getter are matched quad tubes, perfect for high-quality Hi-Fi applications and tube amplifiers. They deliver a powerful and detailed sound, especially suitable for musicians and discerning audiophiles.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eLow frequencies:\u003c\/strong\u003e Controlled and punchy, with well-defined bass that provides a solid and precise foundation.\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eMid frequencies:\u003c\/strong\u003e Articulate and transparent, ideal for enhancing instruments and vocals in a vivid and natural way.\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eHigh frequencies:\u003c\/strong\u003e Crystal-clear and detailed, never fatiguing, making every nuance perfectly audible.\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eOverall sound signature:\u003c\/strong\u003e These tubes offer an open and balanced soundstage, with great dynamic management and instrument separation.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eAdditional Information:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe Sovtek EL84 produces exemplary, warm, and soft distortion. An excellent choice for vintage amplifiers like the VOX AC-30 and similar models. Sovtek EL84s are used by Fender, Crate, and Peavey.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eNOTE:\u003c\/strong\u003e Due to the bulb diameter, these tubes are not suitable for:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eBadCat Model 2R\u003c\/li\u003e\n\u003cli\u003eMarshall DSL201\u003c\/li\u003e\n\u003cli\u003eMarshall DSL401\u003c\/li\u003e\n\u003cli\u003eVOX reissue AC15\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eTubes tested on \u003cstrong\u003eAmplitrex AT-1000 Tube tester\u003c\/strong\u003e:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eTest Conditions:\u003c\/strong\u003e Va = 250V, Vg = -7.3V\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eAverage 100% Gm = 11.3 ; Ia = 48 mA\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eTube 1:\u003c\/strong\u003e\u003cspan style=\"font-family: -apple-system, BlinkMacSystemFont, 'San Francisco', 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif; font-size: 0.875rem;\"\u003e\u0026nbsp;Gm =\u0026nbsp;11.7 ; Ia =\u0026nbsp;47 mA\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eTube 2: \u003c\/strong\u003e\u003cspan style=\"font-family: -apple-system, BlinkMacSystemFont, 'San Francisco', 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif; font-size: 0.875rem;\"\u003eGm =\u0026nbsp;11.7 ; Ia =\u0026nbsp;48 mA\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eTube 3:\u003c\/strong\u003e\u003cspan style=\"font-family: -apple-system, BlinkMacSystemFont, 'San Francisco', 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif; font-size: 0.875rem;\"\u003e\u0026nbsp;Gm =\u0026nbsp;11.4 ; Ia =\u0026nbsp;47 mA\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eTube 4: \u003c\/strong\u003e\u003cspan style=\"font-family: -apple-system, BlinkMacSystemFont, 'San Francisco', 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif; font-size: 0.875rem;\"\u003eGm =\u0026nbsp;11.5 ; Ia =\u0026nbsp;47 mA\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eMicrophony Test\u003c\/li\u003e\n\u003cli\u003eEmission Quality Test\u003c\/li\u003e\n\u003cli\u003eShort Circuit Test\u003c\/li\u003e\n\u003cli\u003eGAS Test\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eCondition:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eNew\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eManufacturing Code:\u003c\/strong\u003e Same Code\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca rel=\"noopener\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"SOVTEK","offers":[{"title":"Default Title","offer_id":49607743668572,"sku":"02528","price":111.38,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_111fafe1-319b-4254-9d6e-ee79da72d5f5.jpg?v=1729866252"},{"product_id":"jan-chs-6v6gt-g-vt-107a-sylvania-black-plates-glass-coating-foil-getter-matched-pair-tubes-made-in-usa-40s","title":"6V6GT\/G JAN-CHS Sylvania Black Plates Glass Coating Foil Getter Matched Pair Tubes USA 1940s","description":"\u003cp\u003e\u003cstrong\u003eJAN-CHS-6V6 GT\/G ( VT-107A ) SYLVANIA Black Plates Glass Coating Foil Getter Matched Pair Tubes MADE IN USA '40s\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-start=\"32\" data-end=\"549\"\u003eThe \u003cstrong data-start=\"35\" data-end=\"71\"\u003eSylvania JAN-CHS-6V6GT\/G VT-107A\u003c\/strong\u003e , with \u003cstrong data-start=\"77\" data-end=\"122\"\u003eBlack Plates, Glass Coating and Foil Getter\u003c\/strong\u003e , manufactured in the \u003cstrong data-start=\"139\" data-end=\"169\"\u003eUSA in the 1940s\u003c\/strong\u003e , are the highest quality military grade tubes, selected for \u003cstrong data-start=\"231\" data-end=\"299\"\u003erigorous standards of reliability and superior sonic performance\u003c\/strong\u003e . The \u003cstrong data-start=\"320\" data-end=\"352\"\u003egraphite-coated glass\u003c\/strong\u003e construction helps reduce RF interference and improve heat dissipation, while the \u003cstrong data-start=\"438\" data-end=\"454\"\u003eblack plates\u003c\/strong\u003e and \u003cstrong data-start=\"460\" data-end=\"475\"\u003efoil getter\u003c\/strong\u003e provide a \u003cstrong data-start=\"502\" data-end=\"546\"\u003erefined, natural, harmonic-rich\u003c\/strong\u003e tone.\u003c\/p\u003e\n\u003cul data-start=\"551\" data-end=\"1377\"\u003e\n\u003cli data-start=\"551\" data-end=\"698\"\u003e\u003cstrong data-start=\"553\" data-end=\"562\"\u003eBass\u003c\/strong\u003e : \u003cstrong data-start=\"564\" data-end=\"596\"\u003eTense, deep and controlled\u003c\/strong\u003e , with a \u003cstrong data-start=\"618\" data-end=\"641\"\u003esolid and articulated\u003c\/strong\u003e low range, perfect for giving \u003cstrong data-start=\"661\" data-end=\"695\"\u003eweight and structure without excess\u003c\/strong\u003e .\u003c\/li\u003e\n\u003cli data-start=\"699\" data-end=\"885\"\u003e\u003cstrong data-start=\"701\" data-end=\"709\"\u003eMids\u003c\/strong\u003e : \u003cstrong data-start=\"711\" data-end=\"756\"\u003eHarmonious, detailed and slightly warm\u003c\/strong\u003e , with a \u003cstrong data-start=\"771\" data-end=\"795\"\u003etransparent and fluid\u003c\/strong\u003e rendering. Voices and instruments emerge with \u003cstrong data-start=\"838\" data-end=\"882\"\u003eexceptional three-dimensionality and realism\u003c\/strong\u003e .\u003c\/li\u003e\n\u003cli data-start=\"886\" data-end=\"1068\"\u003e\u003cstrong data-start=\"888\" data-end=\"896\"\u003eHighs\u003c\/strong\u003e : \u003cstrong data-start=\"898\" data-end=\"929\"\u003eSilky, open and well extended\u003c\/strong\u003e , with a \u003cstrong data-start=\"948\" data-end=\"981\"\u003erefined and harsh-free\u003c\/strong\u003e response, maintaining \u003cstrong data-start=\"994\" data-end=\"1065\"\u003eexcellent clarity and definition without listening fatigue\u003c\/strong\u003e .\u003c\/li\u003e\n\u003cli data-start=\"1069\" data-end=\"1209\"\u003e\u003cstrong data-start=\"1071\" data-end=\"1083\"\u003eDynamics\u003c\/strong\u003e : \u003cstrong data-start=\"1085\" data-end=\"1108\"\u003eResponsive and natural\u003c\/strong\u003e , with \u003cstrong data-start=\"1125\" data-end=\"1152\"\u003efast and well-articulated\u003c\/strong\u003e transients, offering an \u003cstrong data-start=\"1179\" data-end=\"1206\"\u003eengaging and vibrant\u003c\/strong\u003e sound reproduction.\u003c\/li\u003e\n\u003cli data-start=\"1210\" data-end=\"1377\"\u003e\u003cstrong data-start=\"1212\" data-end=\"1226\"\u003eSoundstage\u003c\/strong\u003e : \u003cstrong data-start=\"1228\" data-end=\"1249\"\u003eWide and immersive\u003c\/strong\u003e , with excellent instrument separation and spatial rendering that restores \u003cstrong data-start=\"1330\" data-end=\"1374\"\u003edepth and detail to the soundstage\u003c\/strong\u003e .\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"1379\" data-end=\"1656\"\u003eThanks to their \u003cstrong data-start=\"1396\" data-end=\"1453\"\u003erugged military construction and matched selection\u003c\/strong\u003e , these \u003cstrong data-start=\"1462\" data-end=\"1503\"\u003eJAN-CHS-6V6GT\/G Sylvania Black Plates\u003c\/strong\u003e offer \u003cstrong data-start=\"1512\" data-end=\"1571\"\u003elow microphonics, long life and operational stability\u003c\/strong\u003e , making them \u003cstrong data-start=\"1584\" data-end=\"1653\"\u003eperfect for hi-fi amplifiers and vintage musical instruments\u003c\/strong\u003e .\u003c\/p\u003e\n\u003ch3 data-start=\"1658\" data-end=\"1723\"\u003e\u003cstrong data-start=\"1662\" data-end=\"1721\"\u003e📌 Tips for Using Guitar Amplifiers\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-start=\"1724\" data-end=\"2083\"\u003eThese \u003cstrong data-start=\"1731\" data-end=\"1765\"\u003emilitary-spec Sylvania 6V6GT\/Gs\u003c\/strong\u003e are \u003cstrong data-start=\"1771\" data-end=\"1818\"\u003eideal for vintage and boutique amps\u003c\/strong\u003e benefiting from their \u003cstrong data-start=\"1846\" data-end=\"1922\"\u003enatural compression, large headroom and harmonically rich saturation\u003c\/strong\u003e . They offer \u003cstrong data-start=\"1932\" data-end=\"1962\"\u003ewarm, detailed cleans\u003c\/strong\u003e , with a \u003cstrong data-start=\"1984\" data-end=\"2026\"\u003esmooth, progressive transition to breakup\u003c\/strong\u003e , perfect for genres like blues, jazz and classic rock.\u003c\/p\u003e\n\u003cp data-start=\"2085\" data-end=\"2834\"\u003eThey are distinguished in amplifiers such as:\u003cbr data-start=\"2122\" data-end=\"2125\"\u003e🎸 \u003cstrong data-start=\"2128\" data-end=\"2178\"\u003eFender Deluxe (5A3, 5B3, 5C3, 5D3 Tweed \u0026amp; 5E3)\u003c\/strong\u003e – For a \u003cstrong data-start=\"2194\" data-end=\"2250\"\u003efat, harmonious sound, with rich, dynamic overdrive\u003c\/strong\u003e . \u003cbr data-start=\"2251\" data-end=\"2254\"\u003e🎸 \u003cstrong data-start=\"2257\" data-end=\"2305\"\u003eFender Princeton (pre-Blackface \u0026amp; Blackface)\u003c\/strong\u003e – Ideal for \u003cstrong data-start=\"2319\" data-end=\"2376\"\u003ebright clean sounds and smooth, natural overdrive\u003c\/strong\u003e .\u003cbr data-start=\"2377\" data-end=\"2380\"\u003e🎸 \u003cstrong data-start=\"2383\" data-end=\"2412\"\u003eGibson GA-40 Les Paul Amp\u003c\/strong\u003e – Perfect for \u003cstrong data-start=\"2428\" data-end=\"2492\"\u003esmooth, creamy tones with exceptional dynamic response\u003c\/strong\u003e .\u003cbr data-start=\"2493\" data-end=\"2496\"\u003e🎸 \u003cstrong data-start=\"2499\" data-end=\"2533\"\u003eSupro 1600 Series \u0026amp; Valco Amps\u003c\/strong\u003e – Ideal for \u003cstrong data-start=\"2547\" data-end=\"2613\"\u003ebluesy tones with great response to playing nuances\u003c\/strong\u003e .\u003cbr data-start=\"2614\" data-end=\"2617\"\u003e🎸 \u003cstrong data-start=\"2620\" data-end=\"2643\"\u003eMagnatone 213 \u0026amp; 280\u003c\/strong\u003e – For a \u003cstrong data-start=\"2659\" data-end=\"2710\"\u003espacious, detailed sound with vibrant modulation\u003c\/strong\u003e . \u003cbr data-start=\"2711\" data-end=\"2714\" data-is-only-node=\"\"\u003e🎸 \u003cstrong data-start=\"2717\" data-end=\"2745\"\u003eDr. Z Z-28, Carr Vincent\u003c\/strong\u003e – For those looking for a \u003cstrong data-start=\"2775\" data-end=\"2831\"\u003emodern answer with the warm character of vintage tubes\u003c\/strong\u003e .\u003c\/p\u003e\n\u003cp data-start=\"2836\" data-end=\"3028\"\u003eThese tubes provide \u003cstrong data-start=\"2862\" data-end=\"2923\"\u003enatural sustain and smooth, progressive saturation\u003c\/strong\u003e , making them \u003cstrong data-start=\"2936\" data-end=\"3025\"\u003eone of the best choices for amplifiers with 40s and 50s-inspired circuits\u003c\/strong\u003e .\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eValve tested on \u003cstrong\u003eAMPLITREX AT-1000\u003c\/strong\u003e Tube Tester:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eTest Conditions:\u003c\/strong\u003e \u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003eVa = 250V; Vg2 = 250V; Vg = -12.5V\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eAverage 100%:\u003c\/strong\u003e \u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003eGm = 4.1 ; Ia = 45 mA\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eTest Result:\u003c\/strong\u003e VERY STRONG\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003eValve 1:\u003c\/strong\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cspan\u003eGm = 4.6 ; Ia = 49 mA\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003eValve 2:\u003c\/strong\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cspan\u003eGm = 4.6 ; Ia = 50 mA\u003c\/span\u003e\u003cstrong\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cdiv\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/div\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e Low Noise \u0026amp; Microphonics – Tested and rated for use in hi-fi systems and guitar amplifiers.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eOutput Quality:\u003c\/strong\u003e Excellent – Very strong and stable output, no fluctuations.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eShort circuits and GAS:\u003c\/strong\u003e Absent.\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eConditions:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli data-end=\"371\" data-start=\"221\"\u003e\u003cstrong data-end=\"233\" data-start=\"223\"\u003eCondition:\u003c\/strong\u003e \u003cmeta charset=\"utf-8\"\u003e\u003cstrong\u003eLikely NOS – Excellent emissions and condition,\u003c\/strong\u003e no visible signs of use\u0026nbsp;- \u003cstrong\u003eTested and fully functional.\u003c\/strong\u003e Supplied in our custom box for optimal protection.\u003c\/li\u003e\n\u003cli data-end=\"456\" data-start=\"372\"\u003e\u003cstrong data-end=\"391\" data-start=\"374\"\u003eFunctionality:\u003c\/strong\u003e \u003cstrong data-end=\"419\" data-start=\"392\"\u003eFully operational\u003c\/strong\u003e , with excellent test results.\u003c\/li\u003e\n\u003cli data-end=\"672\" data-start=\"457\"\u003e\u003cstrong data-end=\"484\" data-start=\"459\"\u003eCosmetic Condition:\u003c\/strong\u003e \u003cstrong data-end=\"500\" data-start=\"485\"\u003eVery Good\u003c\/strong\u003e – The lettering is \u003cstrong data-end=\"561\" data-start=\"519\"\u003epartially eroded but still legible\u003c\/strong\u003e . The valve body is in excellent condition, with no obvious signs of wear. \u003cstrong data-end=\"670\" data-start=\"641\"\u003eSee photos for details.\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli data-end=\"797\" data-start=\"673\"\u003e\u003cstrong data-end=\"703\" data-start=\"675\"\u003eManufacturing code:\u003c\/strong\u003e \u003cstrong data-end=\"723\" data-start=\"704\"\u003eUndecipherable\u003c\/strong\u003e , but traceable to Sylvania military productions of the 40s-50s.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca rel=\"noopener\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"SYLVANIA","offers":[{"title":"Default Title","offer_id":54183618773340,"sku":"02832M","price":159.0,"currency_code":"EUR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/2_88c2b114-1fc5-479c-9d42-9ca609e53ed9.jpg?v=1742467381"},{"product_id":"6v6-gta-ge-gray-plates-halo-getter-amplitrex-test-nos-quad-tubes-made-in-usa","title":"6V6GTA GE Gray Plates Halo Getter AMPLITREX Tested Quad VERY STRONG Made in USA","description":"\u003cp\u003e \u003cstrong\u003e6V6 GTA GE Gray Plates Halo Getter AMPLITREX Tested Quad Tubes MADE IN USA\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003ch3\u003e \u003cstrong\u003eDescription:\u003c\/strong\u003e\n\u003c\/h3\u003e\n\n\u003cp data-start=\"309\" data-end=\"689\" class=\"\"\u003e The \u003cstrong data-start=\"312\" data-end=\"368\"\u003e6V6 GTA General Electric Gray Plates with Halo Getter\u003c\/strong\u003e , made in the USA, represent one of the most balanced and musical versions of this classic power tube.\u003cbr data-start=\"496\" data-end=\"499\"\u003e This \u003cstrong data-start=\"506\" data-end=\"540\"\u003equartet tested on Amplitrex\u003c\/strong\u003e offers a \u003cstrong data-start=\"563\" data-end=\"601\"\u003etransparent, dynamic and articulate\u003c\/strong\u003e sound reproduction, with a neutral and refined timbre, suitable for both hi-fi and instrumental applications.\u003c\/p\u003e\n\n \u003cp data-start=\"691\" data-end=\"994\" class=\"\"\u003eThese are not matched tubes, but individually tested with excellent results, ideal for uses where perfect symmetry is not required, such as in \u003cstrong data-start=\"858\" data-end=\"888\"\u003eauto-biasing amplifiers\u003c\/strong\u003e , \u003cstrong data-start=\"905\" data-end=\"921\"\u003esingle-ended configurations.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp data-start=\"996\" data-end=\"1462\" class=\"\"\u003e \u003cstrong data-start=\"996\" data-end=\"1005\"\u003eBass\u003c\/strong\u003e : compact, dry and well controlled, with good articulation even on complex signals.\u003cbr data-start=\"1096\" data-end=\"1099\"\u003e \u003cstrong data-start=\"1099\" data-end=\"1107\"\u003eMids\u003c\/strong\u003e : Clear, smooth and coherent, with natural rendition of vocals and solo instruments.\u003cbr data-start=\"1195\" data-end=\"1198\"\u003e \u003cstrong data-start=\"1198\" data-end=\"1206\"\u003eHighs\u003c\/strong\u003e : soft and transparent, free from harshness, with a pleasant and musical extension.\u003cbr data-start=\"1289\" data-end=\"1292\"\u003e \u003cstrong data-start=\"1292\" data-end=\"1304\"\u003eDynamics\u003c\/strong\u003e : balanced and always ready, with a fast and controlled response even at peaks.\u003cbr data-start=\"1390\" data-end=\"1393\"\u003e \u003cstrong data-start=\"1393\" data-end=\"1407\"\u003eSoundstage\u003c\/strong\u003e : Wide and uncluttered, with a coherent and precise imaging.\u003c\/p\u003e\n\n \u003cp data-start=\"1464\" data-end=\"1648\" class=\"\"\u003eThese \u003cstrong data-start=\"1471\" data-end=\"1497\"\u003e6V6 GTA GE Gray Plates\u003c\/strong\u003e are perfect for those who want a \u003cstrong data-start=\"1538\" data-end=\"1591\"\u003eclean, detailed sound without excessive coloration\u003c\/strong\u003e , with the reliability of a historic American production.\u003c\/p\u003e\n\n\u003cp data-start=\"1655\" data-end=\"1703\" class=\"\"\u003e 🎸 \u003cstrong data-start=\"1658\" data-end=\"1703\"\u003eUse in Guitar and Bass Amplifiers\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp data-start=\"1705\" data-end=\"1937\" class=\"\"\u003e The \u003cstrong data-start=\"1708\" data-end=\"1730\"\u003e6V6 GE Gray Plates\u003c\/strong\u003e is a valve that is also highly appreciated in the musical field, in particular for its \u003cstrong data-start=\"1814\" data-end=\"1855\"\u003ebalanced, compact and musical sound\u003c\/strong\u003e , capable of maintaining transparency and dynamic response even in complex contexts.\u003c\/p\u003e\n\n\u003cp data-start=\"1939\" data-end=\"2172\" class=\"\"\u003e 🔊 \u003cstrong data-start=\"1942\" data-end=\"1979\"\u003eIdeal for musicians looking for:\u003c\/strong\u003e \u003cbr data-start=\"1979\" data-end=\"1982\"\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n\n\u003cli data-start=\"1939\" data-end=\"2172\"\u003e Clean, defined but warm sounds\u003cbr data-start=\"2014\" data-end=\"2017\"\u003e\n\n\u003c\/li\u003e\n\n\u003cli data-start=\"1939\" data-end=\"2172\"\u003e Controlled overdrive, never compressed or muddy\u003cbr data-start=\"2068\" data-end=\"2071\"\u003e\n\n\u003c\/li\u003e\n\n\u003cli data-start=\"1939\" data-end=\"2172\"\u003e Quick and natural response to touch\u003cbr data-start=\"2108\" data-end=\"2111\"\u003e\n\n\u003c\/li\u003e\n\n\u003cli data-start=\"1939\" data-end=\"2172\"\u003e Excellent reliability even under heavy use\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n \u003cp data-start=\"2174\" data-end=\"2474\" class=\"\"\u003e🎸 \u003cstrong data-start=\"2177\" data-end=\"2223\"\u003eAmplifiers where it performs very well:\u003c\/strong\u003e\u003cbr data-start=\"2223\" data-end=\"2226\"\u003e Fender Deluxe \/ Champ \/ Princeton – for classic, clear and defined tones\u003cbr data-start=\"2298\" data-end=\"2301\"\u003e Gibson GA Series – delivers detail and body with great musicality\u003cbr data-start=\"2371\" data-end=\"2374\"\u003e Low-watt boutique amp – ideal for those looking for a dynamic and coherent sound even at low volumes\u003c\/p\u003e\n\n\u003cp data-start=\"2476\" data-end=\"2779\" class=\"\"\u003e 🎯 \u003cstrong data-start=\"2479\" data-end=\"2505\"\u003eNote for guitarists\u003c\/strong\u003e\u003cbr data-start=\"2505\" data-end=\"2508\"\u003e The neutral yet musical tonal response of these 6V6 GEs is perfectly suited to genres such as jazz, blues, country, and classic rock. The sturdy construction and excellent selection ensure reliable sound reproduction even in less than perfectly symmetrical configurations.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch3\u003e \u003cstrong\u003eTest Results:\u003c\/strong\u003e\n\u003c\/h3\u003e\n\n\u003cp\u003e Valve tested on \u003cstrong\u003eAMPLITREX AT-1000\u003c\/strong\u003e Tube Tester:\u003c\/p\u003e\n\n\u003cul\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eTest Conditions:\u003c\/strong\u003e \u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003eVa = 250V; Vg2 = 250V; Vg = -12.5V\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eAverage 100%:\u003c\/strong\u003e \u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003eGm = 4.1 ; Ia = 45 mA\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eTest Result:\u003c\/strong\u003e VERY STRONG\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cp\u003e \u003cmeta charset=\"utf-8\"\u003e\u003cstrong\u003eValve 1:\u003c\/strong\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cspan\u003eGm = 4.3 ; Ia = 47 mA\u003c\/span\u003e\u003c\/p\u003e\n\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003eValve 2:\u003c\/strong\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cspan\u003eGm = 4.3; Ia = 41 mA\u003c\/span\u003e\u003cstrong\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003e \u003cstrong\u003eValve 3:\u003c\/strong\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cspan\u003eGm = 4.1 ; Ia = 40 mA\u003c\/span\u003e\u003c\/p\u003e\n\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003eValve 4:\u003c\/strong\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cspan\u003eGm = 4.2 ; Ia = 40 mA\u003c\/span\u003e\u003c\/p\u003e\n\n\u003cdiv\u003e \u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\n\u003c\/div\u003e\n\n\u003cul\u003e\n\n\u003cli\u003e \u003cspan\u003e\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e\u003cmeta charset=\"utf-8\"\u003e Standard. Tested and compliant for hi-fi use.\u003cmeta charset=\"utf-8\"\u003e or guitar amplifiers.\u003c\/span\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e \u003cspan\u003e\u003cstrong\u003eOutput Quality:\u003c\/strong\u003e Excellent – ​​Very strong and stable output, no fluctuations.\u003c\/span\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e \u003cspan\u003e\u003cstrong\u003eShort circuits and GAS:\u003c\/strong\u003e Absent.\u003c\/span\u003e\n\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch3\u003e \u003cstrong\u003eConditions:\u003c\/strong\u003e\n\u003c\/h3\u003e\n\n\u003cul\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eCondition:\u003c\/strong\u003e Vintage - Tested and working - In our custom box.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eFunctionality:\u003c\/strong\u003e Fully functional.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eAesthetic condition:\u003c\/strong\u003e Fair – Writing almost completely faded, with signs of wear on the feet. See photos for details.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\n\u003c\/li\u003e\n\n \u003cli\u003e\u003cstrong\u003eManufacturing Code:\u003cmeta charset=\"utf-8\"\u003e \u003cspan\u003eCG - January 1985\u003c\/span\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cp\u003e \u003cstrong\u003e\u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003e\n\u003ca href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" title=\"Why our tubes are different – ​​the VTT protocol that improves sound, reliability and durability\" rel=\"noopener\" target=\"_blank\"\u003eFind out why our valves are different →\u003c\/a\u003e\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e","brand":"GE","offers":[{"title":"Default Title","offer_id":54280876687708,"sku":"02870L","price":94.9,"currency_code":"EUR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_73ccd882-bab1-4a5a-bf60-32887545326e.jpg?v=1744029330"},{"product_id":"6550-jj-matched-quad-signature-burned-24h-amplitrex-tested-vacuum-tubes-treasures","title":"6550 JJ Signature Matched Quad - NEW - 24h Burn-in - Amplitrex Curve Tested Tubes","description":"\u003cp data-end=\"303\" data-start=\"205\"\u003e\u003cstrong\u003e6550 JJ Signature Matched Quad - NEW - 24h Burn-in - Amplitrex Curve Tested Tubes\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp data-end=\"424\" data-start=\"304\"\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong data-end=\"412\" data-start=\"388\"\u003eThe 6550 JJ Signature\u003c\/strong\u003e takes everything that's good about the 6550 JJ - \u003cstrong data-end=\"491\" data-start=\"455\"\u003edynamics, headroom, and balance\u003c\/strong\u003e - and takes it to the next level.\u003cbr data-end=\"533\" data-start=\"530\"\u003e Thanks to \u003cstrong data-end=\"564\" data-start=\"543\"\u003e24-hour burn-in\u003c\/strong\u003e and \u003cstrong data-end=\"617\" data-start=\"570\"\u003ematching on real Amplitrex dynamic curves\u003c\/strong\u003e , the sound gains in \u003cstrong data-end=\"677\" data-start=\"640\"\u003eprecision, detail and stability\u003c\/strong\u003e .\u003cbr data-end=\"681\" data-start=\"678\"\u003e The \u003cstrong data-is-only-node=\"\" data-end=\"692\" data-start=\"683\"\u003ebass\u003c\/strong\u003e becomes more controlled, the \u003cstrong data-end=\"741\" data-start=\"722\"\u003estereo image\u003c\/strong\u003e more focused, the \u003cstrong data-end=\"770\" data-start=\"762\"\u003evocals\u003c\/strong\u003e more natural. \u003cbr data-end=\"787\" data-start=\"784\"\u003eEach quartet is \u003cstrong data-end=\"826\" data-start=\"804\"\u003ehand-selected\u003c\/strong\u003e and accompanied by an \u003cstrong data-end=\"874\" data-start=\"849\"\u003eindividual test card\u003c\/strong\u003e with the actual curve graph.\u003cbr data-end=\"911\" data-start=\"908\"\u003e \u003cstrong data-end=\"964\" data-start=\"911\"\u003eNo generic pre-prints, no invented data\u003c\/strong\u003e : each curve is unique, like each valve.\u003c\/p\u003e\n\n\u003chr data-end=\"813\" data-start=\"810\"\u003e\n\n\u003ch3 data-end=\"890\" data-start=\"815\"\u003e Signature Selection Process – Advanced Technique and Total Transparency\u003c\/h3\u003e\n\n\u003cul\u003e\n\n\u003cli data-end=\"1621\" data-start=\"1520\"\u003e \u003cstrong data-end=\"1549\" data-start=\"1533\"\u003eReal 24-hour\u003c\/strong\u003e burn-in on Maxi-Burn station, to stabilize electrical characteristics\u003c\/li\u003e\n\n\u003cli data-end=\"1734\" data-start=\"1624\"\u003e Testing of the \u003cstrong data-end=\"1655\" data-start=\"1634\"\u003eAmplitrex AT-1000\u003c\/strong\u003e at real operating voltages, with dynamic matching and symmetry verification\u003c\/li\u003e\n\n\u003cli data-end=\"1823\" data-start=\"1737\"\u003e Complete analysis of \u003cstrong data-end=\"1787\" data-start=\"1762\"\u003echaracteristic curves\u003c\/strong\u003e , not just static values ​​(Gm, Ip)\u003c\/li\u003e\n\n\u003cli data-end=\"1902\" data-start=\"1826\"\u003e Technical attachment with \u003cstrong data-end=\"1873\" data-start=\"1849\"\u003eprinted real curves\u003c\/strong\u003e and sealed numbered envelope\u003c\/li\u003e\n\n \u003cli data-end=\"1998\" data-start=\"1905\"\u003eHandcrafted selection: Each quartet is \u003cstrong data-end=\"1970\" data-start=\"1947\"\u003eformed manually\u003c\/strong\u003e , not in factory batches \u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003chr data-end=\"1599\" data-start=\"1596\"\u003e\n\n\u003ch3 data-end=\"1621\" data-start=\"1601\"\u003e Sound character\u003c\/h3\u003e\n\n\u003cul\u003e\n\n\u003cli data-start=\"2087\" data-end=\"2155\"\u003e\n\n \u003cstrong data-start=\"2087\" data-end=\"2096\"\u003eBass\u003c\/strong\u003e : solid and tight, with excellent articulation and control\u003c\/li\u003e\n\n\u003cli data-start=\"2158\" data-end=\"2203\"\u003e\n\n \u003cstrong data-start=\"2158\" data-end=\"2166\"\u003eMedium\u003c\/strong\u003e : transparent, natural, realistic\u003c\/li\u003e\n\n\u003cli data-start=\"2206\" data-end=\"2261\"\u003e\n\n \u003cstrong data-start=\"2206\" data-end=\"2214\"\u003eHighs\u003c\/strong\u003e : extended, never aggressive, rich in detail\u003c\/li\u003e\n\n\u003cli data-start=\"2264\" data-end=\"2316\"\u003e\n\n \u003cstrong data-start=\"2264\" data-end=\"2276\"\u003eDynamics\u003c\/strong\u003e : Reactive yet fluid, wide and natural\u003c\/li\u003e\n\n\u003cli data-start=\"2319\" data-end=\"2370\"\u003e\n\n \u003cstrong data-start=\"2319\" data-end=\"2333\"\u003eSoundstage\u003c\/strong\u003e : stable, deep and well structured\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cp data-start=\"2372\" data-end=\"2567\"\u003e 🎧 \u003cem data-start=\"2375\" data-end=\"2417\"\u003eIdeal for high-end Hi-Fi systems\u003c\/em\u003e (McIntosh MC275, Audio Research, Conrad Johnson)\u003cbr data-start=\"2466\" data-end=\"2469\"\u003e 🎸 \u003cem data-start=\"2472\" data-end=\"2518\"\u003ePerfect for boutique music amplifiers\u003c\/em\u003e with ample headroom and natural dynamic response.\u003c\/p\u003e\n\n\u003chr data-end=\"1599\" data-start=\"1596\"\u003e\n\n\u003ch3\u003e Test Specifications\u003c\/h3\u003e\n\n \u003cp data-end=\"619\" data-start=\"434\"\u003eTubes tested on \u003cstrong data-end=\"486\" data-start=\"453\"\u003ethe Amplitrex AT-1000 Tube Tester\u003c\/strong\u003e at real-world operating voltages, with measurements taken after a 10-minute warm-up.\u003c\/p\u003e\n\n\u003cp data-end=\"653\" data-start=\"621\"\u003e \u003cstrong data-end=\"651\" data-start=\"621\"\u003eAdditional tests performed:\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n\n\u003cli data-end=\"727\" data-start=\"656\"\u003e\n\n \u003cstrong data-end=\"674\" data-start=\"656\"\u003eMicrophonics:\u003c\/strong\u003e Complies with hi-fi and musical instrument standards.\u003c\/li\u003e\n\n\u003cli data-end=\"809\" data-start=\"730\"\u003e\n\n \u003cstrong data-end=\"757\" data-start=\"730\"\u003eOutput quality:\u003c\/strong\u003e excellent – ​​stable, strong and smooth output.\u003c\/li\u003e\n\n\u003cli data-end=\"847\" data-start=\"812\"\u003e\n\n \u003cstrong data-end=\"836\" data-start=\"812\"\u003eShort circuits \/ GAS:\u003c\/strong\u003e absent.\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cp data-end=\"1039\" data-start=\"849\"\u003e Our \u003cstrong data-end=\"880\" data-start=\"859\"\u003eSignature tubes\u003c\/strong\u003e are not factory selections, but \u003cstrong data-end=\"972\" data-start=\"916\"\u003ehand-measured and matched precision instruments\u003c\/strong\u003e , designed for those seeking the essence of sound, not a printed number.\u003c\/p\u003e\n\n\u003chr data-end=\"1599\" data-start=\"1596\"\u003e\n\n\u003ch3\u003e Conditions\u003c\/h3\u003e\n\n\u003cul\u003e\n\n\u003cli\u003e Supplied in our custom box for optimal protection.\u003c\/li\u003e\n\n\u003cli\u003e Functionality: impeccable\u003c\/li\u003e\n\n \u003cli\u003e\n\u003cstrong\u003eFactory-new\u003c\/strong\u003e valves, tested and in perfect working order. \u003cstrong\u003e24-month legal warranty\u003c\/strong\u003e (consumers, Legislative Decree 206\/2005). \u003cstrong\u003eB2B: Articles 1490 et seq. of the Italian Civil Code apply.\u003c\/strong\u003e\u003cbr\u003e \u003cstrong\u003eReturns for sound preferences\/tube rolling are not accepted. 14-day returns are\u003c\/strong\u003e only accepted with an \u003cstrong\u003eintact\u003c\/strong\u003e seal and \u003cstrong\u003eunused\u003c\/strong\u003e tube. The warranty covers only \u003cstrong\u003eoriginal defects\u003c\/strong\u003e ; \u003cstrong\u003ewear and tear\u003c\/strong\u003e , \u003cstrong\u003eimproper use\u003c\/strong\u003e , and \u003cstrong\u003etampering\u003c\/strong\u003e are excluded.\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003ch3\u003e Additional Information\u003c\/h3\u003e\n\n\u003cp\u003e JJ tubes may exhibit \u003cstrong\u003eslight variations in glass bulb height\u003c\/strong\u003e , with no impact on performance.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003cp\u003e \u003cspan style=\"color: rgb(43, 0, 255);\"\u003e\u003cstrong\u003eFAQ - Frequently Asked Questions:\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eQuestion:\u003c\/strong\u003e What do dynamic matching, full symmetry verification, and active curve analysis mean? Aren't the test data on the label enough?\u003cbr\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e \n\u003cstrong\u003eAnswer:\u003c\/strong\u003e The static data on the label tells us \"how\" a tube works. The actual curve shows \"how\" it works. It's a bit like knowing that a car can go 200 km\/h...but without knowing how it accelerates, brakes, or holds its course. The dynamic curves allow us to select four tubes that \"drive\" in the same way during the musical journey.\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cul\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eQuestion:\u003c\/strong\u003e But on a sonic level, what really changes compared to a standard matching?\u003c\/li\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eAnswer:\u003c\/strong\u003e The sound gains in precision, detail, and stability. Bass is more controlled, the stereo image more focused, vocals more natural. Dynamic matching reduces tube dissonance and transforms the listening experience: more musical, more believable, more engaging.\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cul\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eQuestion:\u003c\/strong\u003e After installation, do they sound loud right away? Or do they need to be broken in?\u003cbr\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e \n\u003cstrong\u003eAnswer:\u003c\/strong\u003e They sound good right out of the box, but they get better with time. After just 50 hours, the bass becomes tight, and around 100 hours, the tonal balance stabilizes. Breaking in is part of the process that makes the sound more natural and engaging.\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cul\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eQuestion:\u003c\/strong\u003e What is 24-hour burn-in? And what about break-in?\u003c\/li\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eAnswer:\u003c\/strong\u003e No, it's a different technical step: before being tested, the valves are left on for 24 hours under controlled conditions. This serves to stabilize the internal parameters and eliminate unstable units. This way, the customer receives only reliable, already \"settled\" valves.\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e 🔍 Find out what we really think: \u003ca rel=\"noopener\" title=\"Complete Guide to the 6550 JJ Valve\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/guida-completa-alla-valvola-6550-jj\" target=\"_blank\"\u003eread our complete guide to the 6550 JJ.\u003c\/a\u003e\u003c\/p\u003e","brand":"JJ ELECTRONICS","offers":[{"title":"Default Title","offer_id":54426908295516,"sku":"02898","price":269.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_757437cb-572f-46d8-901f-74e094696f69.jpg?v=1760114963"},{"product_id":"6l6gc-rca-black-plates-halo-side-getter-matched-pair-usa-tubes-tested-strong-amplitrex","title":"6L6GC RCA Black Plates – Halo Side Getter – Matched Pair – USA Tubes – Tested Strong Amplitrex","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003e6L6GC RCA Black Plates Side Halo Getter Matched Pair Tubes MADE IN USA\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-end=\"669\" data-start=\"208\"\u003eThe \u003cstrong data-end=\"224\" data-start=\"211\"\u003e6L6GC RCA\u003c\/strong\u003e , in this precious version with \u003cstrong data-end=\"274\" data-start=\"258\"\u003eblack plates\u003c\/strong\u003e , \u003cstrong data-end=\"302\" data-start=\"276\"\u003elateral halo getter\u003c\/strong\u003e and symmetrical internal structure, represent one of the reference standards in the history of American power tubes. The robust construction, combined with the historically recognized tonal quality of the RCA brand, gives life to a \u003cstrong data-end=\"587\" data-start=\"549\"\u003emusical, authoritative and transparent\u003c\/strong\u003e tube, capable of returning a faithful, rich and dynamically controlled reproduction.\u003c\/p\u003e\n\u003cp data-end=\"899\" data-start=\"671\"\u003eThis \u003cstrong data-end=\"696\" data-start=\"678\"\u003ematched pair\u003c\/strong\u003e ensures uniformity between channels and consistent performance in high-fidelity contexts, whether in \u003cstrong data-end=\"824\" data-start=\"798\"\u003epush-pull stereo hi-fi\u003c\/strong\u003e or in high-end, vintage or boutique \u003cstrong data-end=\"863\" data-start=\"833\"\u003eguitar amplifiers\u003c\/strong\u003e .\u003c\/p\u003e\n\u003cp data-end=\"1184\" data-start=\"906\"\u003e\u003cstrong data-end=\"915\" data-start=\"906\"\u003eBass\u003c\/strong\u003e : Deep and firm. The low end is \u003cstrong data-end=\"969\" data-start=\"953\"\u003ewell anchored\u003c\/strong\u003e , with \u003cstrong data-end=\"1023\" data-start=\"975\"\u003econtrolled punch and excellent articulation\u003c\/strong\u003e . The bass is not intrusive, but supports the soundstage with \u003cstrong data-end=\"1105\" data-start=\"1080\"\u003eauthority and precision\u003c\/strong\u003e , making this tube ideal for systems with extended frequency response.\u003c\/p\u003e\n\u003cp data-end=\"1464\" data-start=\"1186\"\u003e\u003cstrong data-end=\"1194\" data-start=\"1186\"\u003eMids\u003c\/strong\u003e : full-bodied and centered. The timbral heart of the RCAs lies in the \u003cstrong data-end=\"1303\" data-start=\"1256\"\u003efull, natural and dynamically rich mids\u003c\/strong\u003e . Voices are \u003cstrong data-end=\"1341\" data-start=\"1318\"\u003ecredible and direct\u003c\/strong\u003e , acoustic instruments emerge with \u003cstrong data-end=\"1416\" data-start=\"1379\"\u003epresence and well-defined harmonics\u003c\/strong\u003e , without ever artificially coloring the signal.\u003c\/p\u003e\n\u003cp data-end=\"1729\" data-start=\"1466\"\u003e\u003cstrong data-end=\"1474\" data-start=\"1466\"\u003eHighs\u003c\/strong\u003e : refined and present. The high range is \u003cstrong data-end=\"1544\" data-start=\"1524\"\u003eextended but silky\u003c\/strong\u003e , with a \u003cstrong data-end=\"1586\" data-start=\"1553\"\u003edetail finely integrated\u003c\/strong\u003e into the musical context. No tendency towards excessive brightness: only \u003cstrong data-end=\"1699\" data-start=\"1661\"\u003etransparency and natural definition\u003c\/strong\u003e , even during prolonged listening.\u003c\/p\u003e\n\u003cp data-end=\"2002\" data-start=\"1731\"\u003e\u003cstrong data-end=\"1743\" data-start=\"1731\"\u003eDynamics\u003c\/strong\u003e : solid and progressive. The response to transients is \u003cstrong data-end=\"1820\" data-start=\"1795\"\u003efast but controlled\u003c\/strong\u003e , with \u003cstrong data-end=\"1875\" data-start=\"1830\"\u003eexcellent linearity even at high volume\u003c\/strong\u003e . The power output is fluid, with a \u003cstrong data-end=\"1980\" data-start=\"1918\"\u003edynamic capacity that supports micro and macro variations\u003c\/strong\u003e without ever collapsing.\u003c\/p\u003e\n\u003cp data-end=\"2208\" data-start=\"2004\"\u003e\u003cstrong data-end=\"2018\" data-start=\"2004\"\u003eSoundstage\u003c\/strong\u003e : wide and stable. The stereo image is \u003cstrong data-end=\"2104\" data-start=\"2063\"\u003ecoherent, deep and well-layered\u003c\/strong\u003e , with \u003cstrong data-end=\"2151\" data-start=\"2110\"\u003eexcellent positioning of the instruments\u003c\/strong\u003e and a \u003cstrong data-end=\"2207\" data-start=\"2181\"\u003ecredible and enveloping\u003c\/strong\u003e spatial reconstruction.\u003c\/p\u003e\n\u003cp data-end=\"2639\" data-start=\"2215\"\u003e🎧 \u003cstrong data-end=\"2265\" data-start=\"2218\"\u003eUse in Push-Pull Stereo Hi-Fi Amplifiers\u003c\/strong\u003e \u003cbr data-end=\"2268\" data-start=\"2265\"\u003eThe 6L6GC RCA Black Plates are particularly suited for 6L6GC-compatible \u003cstrong data-end=\"2358\" data-start=\"2342\"\u003eClass AB\u003c\/strong\u003e amplifiers (e.g. \u003cstrong data-end=\"2414\" data-start=\"2386\"\u003eHarman Kardon Citation V\u003c\/strong\u003e , \u003cstrong data-end=\"2432\" data-start=\"2416\"\u003eHeathkit W5M\u003c\/strong\u003e , \u003cstrong data-end=\"2450\" data-start=\"2434\"\u003ePilot SA-260\u003c\/strong\u003e , or high-end homebrew designs). They deliver a \u003cstrong data-end=\"2525\" data-start=\"2503\"\u003eneutral yet musical\u003c\/strong\u003e sound, with dynamic, emotional output that enhances any musical genre, from classical to acoustic rock.\u003c\/p\u003e\n\u003cp data-end=\"3024\" data-start=\"2641\"\u003e🎸 \u003cstrong data-end=\"2689\" data-start=\"2644\"\u003eUse in Guitar and Bass Amplifiers\u003c\/strong\u003e \u003cbr data-end=\"2692\" data-start=\"2689\"\u003eAmong the \u003cstrong data-end=\"2745\" data-start=\"2707\"\u003emost appreciated tubes in Fender history\u003c\/strong\u003e , the RCA 6L6GC are synonymous with \u003cstrong data-end=\"2800\" data-start=\"2777\"\u003ecreamy saturation\u003c\/strong\u003e , \u003cstrong data-end=\"2842\" data-start=\"2802\"\u003eclean and harmonic-rich headroom\u003c\/strong\u003e , \u003cstrong data-end=\"2881\" data-start=\"2844\"\u003eprogressive musical compression\u003c\/strong\u003e . Ideal for amps such as \u003cstrong data-end=\"2920\" data-start=\"2905\"\u003eTwin Reverb\u003c\/strong\u003e , \u003cstrong data-end=\"2933\" data-start=\"2922\"\u003eBassman\u003c\/strong\u003e , \u003cstrong data-end=\"2949\" data-start=\"2935\"\u003eBandmaster\u003c\/strong\u003e , where the sound must be \u003cstrong data-end=\"3023\" data-start=\"2977\"\u003ealive, dynamic and ready to react to the touch\u003c\/strong\u003e .\u003c\/p\u003e\n\u003cp data-end=\"3372\" data-start=\"3026\"\u003e🎯 \u003cstrong data-end=\"3061\" data-start=\"3029\"\u003eNote for audiophiles and technicians\u003c\/strong\u003e \u003cbr data-end=\"3064\" data-start=\"3061\"\u003eAn \u003cstrong data-end=\"3087\" data-start=\"3076\"\u003eiconic\u003c\/strong\u003e valve, representing the American tonal standard par excellence. The \u003cstrong data-end=\"3175\" data-start=\"3155\"\u003eRCA Black Plates\u003c\/strong\u003e , in \u003cstrong data-end=\"3211\" data-start=\"3195\"\u003ematched pair\u003c\/strong\u003e configuration, guarantee \u003cstrong data-end=\"3284\" data-start=\"3226\"\u003eelectrical coherence, tonal balance and a unique voice\u003c\/strong\u003e , appreciated both in high fidelity systems and in professional musical instruments.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eTested on AMPLITREX AT-1000 Tube tester:\u003c\/strong\u003e\u003cbr\u003eVf = 6.3V; Va = 350; Vg2 = 250; Vg1 = -18V\u003cbr\u003eAverage 100% Gm = 5200 ; Ia = 54 mA\u003cbr\u003e\u003cstrong\u003eTEST RESULT:\u003c\/strong\u003e\u003c\/span\u003e \u003cstrong\u003eVERY\u003c\/strong\u003e \u003cstrong\u003eSTRONG\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eValve 1: Gm = 4740 ; Ia = 55 mA\u003cbr\u003eValve 2: Gm = 4900 ; Ia = 59 mA\u003cstrong\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cdiv\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/div\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e\u003cmeta charset=\"utf-8\"\u003e Standard. Tested and compliant for use in hi-fi and guitar amplifiers.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eOutput Quality:\u003c\/strong\u003e Excellent – Very strong and stable output, no fluctuations.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eShort circuits and GAS:\u003c\/strong\u003e Absent.\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eConditions:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eCondition:\u003c\/strong\u003e Vintage Tubes - Tested and in perfect working order. Supplied in our custom box for optimum protection.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eFunctionality:\u003c\/strong\u003e Fully functional.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eAesthetic Condition:\u003c\/strong\u003e Sufficient – Writing completely disappeared, with obvious signs of wear on the base or feet. See photos for details.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eManufacturing Code:\u003c\/strong\u003e None. Manufacturing year detected by internal structure - Made in USA in the 1960s.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca rel=\"noopener\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"RCA","offers":[{"title":"Default Title","offer_id":54811554840924,"sku":"02977L","price":149.9,"currency_code":"EUR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/3_ca7cb761-06cc-4b60-81d5-b56f1bcb3beb.jpg?v=1750685836"},{"product_id":"45-st-rca-cunningham-matched-pair-black-plates-foil-dimpled-getter-radiotron-tubes-made-in-usa-1930s","title":"45 ST RCA Cunningham Matched Pair Black Plates Foil Dimpled Getter Radiotron Tubes Made in USA 1930's","description":"\u003cp\u003e\u0026nbsp;\u003cstrong data-start=\"96\" data-end=\"210\"\u003e45 ST RCA Cunningham Matched Pair – Black Plates – Foil Dimpled Getter – Radiotron Tubes – Made in USA – 1930s\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"212\" data-end=\"619\"\u003e\u003cstrong data-start=\"212\" data-end=\"228\"\u003eDescription:\u003c\/strong\u003e\u003cbr data-start=\"228\" data-end=\"231\"\u003eThis matched pair of RCA Cunningham 45 ST tubes from the 1930s represents one of the most iconic and refined voices in early-era American tube production. Featuring \u003cstrong data-start=\"396\" data-end=\"412\"\u003eblack plates\u003c\/strong\u003e, \u003cstrong data-start=\"414\" data-end=\"437\"\u003efoil dimpled getter\u003c\/strong\u003e, and a more modern \u003cstrong data-start=\"457\" data-end=\"484\"\u003eST-style glass envelope\u003c\/strong\u003e (as opposed to globe types), these tubes retain the full musicality that made the 45 a benchmark in low-power single-ended amplifiers.\u003c\/p\u003e\n\u003cp data-start=\"621\" data-end=\"798\"\u003eThanks to the precise matching, these two tubes offer \u003cstrong data-start=\"675\" data-end=\"710\"\u003esymmetrical electrical behavior\u003c\/strong\u003e, ideal for dual mono or stereo single-ended applications with high-efficiency speakers.\u003c\/p\u003e\n\u003cp data-start=\"805\" data-end=\"837\"\u003e\u003cstrong data-start=\"805\" data-end=\"837\"\u003eTonality and Sound Signature\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"839\" data-end=\"1064\"\u003e\u003cstrong data-start=\"839\" data-end=\"848\"\u003eBass:\u003c\/strong\u003e\u003cbr data-start=\"848\" data-end=\"851\"\u003eLight but articulate. The low-end is precise, dry, and natural, with excellent timing and rhythmic articulation. Perfect for those who prefer an agile response that does not mask the details in the lower midrange.\u003c\/p\u003e\n\u003cp data-start=\"1066\" data-end=\"1364\"\u003e\u003cstrong data-start=\"1066\" data-end=\"1079\"\u003eMidrange:\u003c\/strong\u003e\u003cbr data-start=\"1079\" data-end=\"1082\"\u003eExceptionally transparent. This region is the real strength of this pair: lifelike vocals, three-dimensional acoustic instruments, and a fluidity that makes every listening session natural and engaging. The sound is present but never intrusive, with an extremely fine tonal texture.\u003c\/p\u003e\n\u003cp data-start=\"1366\" data-end=\"1536\"\u003e\u003cstrong data-start=\"1366\" data-end=\"1376\"\u003eHighs:\u003c\/strong\u003e\u003cbr data-start=\"1376\" data-end=\"1379\"\u003eSweet and airy. The treble is extended yet smooth, with a fine grain and no trace of harshness. Excellent rendition of ambient \"air\" and microdynamic detail.\u003c\/p\u003e\n\u003cp data-start=\"1538\" data-end=\"1754\"\u003e\u003cstrong data-start=\"1538\" data-end=\"1551\"\u003eDynamics:\u003c\/strong\u003e\u003cbr data-start=\"1551\" data-end=\"1554\"\u003eNatural and progressive. The response to transients is fast and coherent, never compressed or artificial. These 45s reproduce every change in intensity with musicality and clarity, even at low volume.\u003c\/p\u003e\n\u003cp data-start=\"1756\" data-end=\"2001\"\u003e\u003cstrong data-start=\"1756\" data-end=\"1771\"\u003eSoundstage:\u003c\/strong\u003e\u003cbr data-start=\"1771\" data-end=\"1774\"\u003eIntimate but precise. The stereo image is centered, well-organized, and realistically layered, with excellent depth and source localization. The stage isn’t as wide as higher-power tubes, but it is cohesive and very believable.\u003c\/p\u003e\n\u003cp data-start=\"2008\" data-end=\"2344\"\u003e🎧 \u003cstrong data-start=\"2011\" data-end=\"2048\"\u003eUse in Single-Ended Hi-Fi Systems\u003c\/strong\u003e\u003cbr data-start=\"2048\" data-end=\"2051\"\u003ePerfect for \u003cstrong data-start=\"2063\" data-end=\"2092\"\u003eSET (Single-Ended Triode)\u003c\/strong\u003e amplifiers offering 1.5 – 2 watts per channel, paired with high-efficiency loudspeakers. This matched pair is ideal for those seeking an \u003cstrong data-start=\"2230\" data-end=\"2261\"\u003eorganic, fluid, and musical\u003c\/strong\u003e presentation, with special focus on vocal naturalness and overall tonal coherence.\u003c\/p\u003e\n\u003cp data-start=\"2351\" data-end=\"2721\"\u003e🎯 \u003cstrong data-start=\"2354\" data-end=\"2393\"\u003eNote for Collectors and Technicians\u003c\/strong\u003e\u003cbr data-start=\"2393\" data-end=\"2396\"\u003eThese RCA Cunningham Radiotron 45 ST tubes strike a rare balance between historical value, construction quality, and musical finesse. The \u003cstrong data-start=\"2534\" data-end=\"2569\"\u003edual-brand RCA Cunningham label\u003c\/strong\u003e, typical of 1930s production, adds collectible appeal. A matched pair ideal not only for listening, but for \u003cstrong data-start=\"2678\" data-end=\"2720\"\u003eexperiencing the sound of a bygone era\u003c\/strong\u003e.\u003c\/p\u003e\n\u003chr data-start=\"2723\" data-end=\"2726\"\u003e\n\u003cp data-start=\"2728\" data-end=\"2970\"\u003e\u003cstrong data-start=\"2728\" data-end=\"2745\"\u003eTest Results:\u003c\/strong\u003e\u003cbr data-start=\"2745\" data-end=\"2748\"\u003eTested with \u003cstrong data-start=\"2760\" data-end=\"2793\"\u003eAMPLITREX AT-1000 Tube Tester\u003c\/strong\u003e\u003cbr data-start=\"2793\" data-end=\"2796\"\u003eMeasurements taken after 10 minutes of warm-up.\u003cbr data-start=\"2843\" data-end=\"2846\"\u003eTest conditions: Vf = 2.5V ; Va = 275V ; Vg = -54.8V\u003cbr data-start=\"2898\" data-end=\"2901\"\u003e100% Reference: Gm = 2000 ; Ia = 36 mA\u003cbr data-start=\"2939\" data-end=\"2942\"\u003e\u003cstrong data-start=\"2942\" data-end=\"2970\"\u003eTest Result: STRONG\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"2728\" data-end=\"2970\"\u003e\u003cstrong data-start=\"2974\" data-end=\"2985\"\u003eTube 1:\u003c\/strong\u003e Gm = 1760 ; Ia = 26 mA\u003c\/p\u003e\n\u003cp data-start=\"2728\" data-end=\"2970\"\u003e\u003cstrong data-start=\"3013\" data-end=\"3024\"\u003eTube 2:\u003c\/strong\u003e Gm = 1570 ; Ia = 25 mA\u003c\/p\u003e\n\u003cp data-start=\"3051\" data-end=\"3082\"\u003e\u003cstrong data-start=\"3051\" data-end=\"3082\"\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong data-start=\"3086\" data-end=\"3103\"\u003eMicrophonics:\u003c\/strong\u003e Standard – Tested and approved for hi-fi and guitar amp use.\u003c\/li\u003e\n\u003cli\u003e\u003cstrong data-start=\"3169\" data-end=\"3190\"\u003eEmission Quality:\u003c\/strong\u003e Excellent – Very strong and stable emission, with no fluctuations.\u003c\/li\u003e\n\u003cli\u003e\u003cstrong data-start=\"3262\" data-end=\"3279\"\u003eShorts \u0026amp; Gas:\u003c\/strong\u003e None detected.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr data-start=\"3296\" data-end=\"3299\"\u003e\n\u003cp data-start=\"3301\" data-end=\"3317\"\u003e\u003cstrong data-start=\"3301\" data-end=\"3315\"\u003eCondition:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eVintage tubes – tested and fully functional.\u003c\/li\u003e\n\u003cli\u003eSupplied in our \u003cstrong data-start=\"3385\" data-end=\"3410\"\u003ecustom protective box\u003c\/strong\u003e.\u003c\/li\u003e\n\u003cli\u003e\u003cstrong data-start=\"3416\" data-end=\"3431\"\u003eFunctional:\u003c\/strong\u003e Fully operational.\u003c\/li\u003e\n\u003cli\u003e\u003cstrong data-start=\"3455\" data-end=\"3478\"\u003eCosmetic Condition:\u003c\/strong\u003e Very Good – Print is clearly legible; light signs of age but no major flaws. See photos for details.\u003c\/li\u003e\n\u003cli\u003e\u003cstrong data-start=\"3584\" data-end=\"3607\"\u003eManufacturing Code:\u003c\/strong\u003e Not present – manufacturing period based on internal structure. Made in USA, 1930s.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca rel=\"noopener\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"RCA","offers":[{"title":"Default Title","offer_id":55039873417564,"sku":"03011","price":249.9,"currency_code":"EUR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/8_a321d9b2-6138-4f0e-8553-02de0de6428f.jpg?v=1752843590"},{"product_id":"6g6g-vt-198a-rca-nos-nib-💎amplitrex-tested-tube-black-plates-power-pentode-usa","title":"6G6G = VT-198A = 6G6GT RCA NOS NIB Tested Tube Black Plates Square Getter Power Pentode USA","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003eJAN CRC 6G6G ( VT-198A ) RCA NOS NIB Black Plates Square Getter Power Pentode Tested Tube MADE IN USA '60\u003c\/strong\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-start=\"258\" data-end=\"560\"\u003eThis \u003cstrong data-start=\"265\" data-end=\"291\"\u003eJAN CRC 6G6G \/ VT-198A\u003c\/strong\u003e , produced by \u003cstrong data-start=\"305\" data-end=\"312\"\u003eRCA\u003c\/strong\u003e in \u003cstrong data-start=\"317\" data-end=\"325\"\u003e1960\u003c\/strong\u003e , is a power amplifier pentode designed for military applications (JAN = Joint Army Navy). It is in \u003cstrong data-start=\"436\" data-end=\"470\"\u003eNOS (New Old Stock) condition\u003c\/strong\u003e , never used, and comes in \u003cstrong data-start=\"510\" data-end=\"557\"\u003eits original sealed military packaging\u003c\/strong\u003e .\u003c\/p\u003e\n\u003cp data-start=\"562\" data-end=\"947\"\u003eInternally it features \u003cstrong data-start=\"595\" data-end=\"611\"\u003eblack plates\u003c\/strong\u003e , a square getter, and a sturdy, well-centered symmetrical structure. The 6G6G is a variant of the 6V6 with slightly different operating characteristics, such as a lower anode voltage, a rounder dynamic response, and a smoother timbre, making it ideal for low-power but highly refined amplifiers.\u003c\/p\u003e\n\u003ch3 data-start=\"954\" data-end=\"1010\"\u003e\u003cstrong data-start=\"960\" data-end=\"1010\"\u003eTimbre characteristics and sound description\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-start=\"1012\" data-end=\"1238\"\u003e\u003cstrong data-start=\"1012\" data-end=\"1022\"\u003eBass:\u003c\/strong\u003e\u003cbr data-start=\"1022\" data-end=\"1025\"\u003eDry and controlled. They offer a quick and clean response, without bloat or excess, restoring the right weight to the instruments without invading the midrange. Excellent for listening in controlled environments.\u003c\/p\u003e\n\u003cp data-start=\"1240\" data-end=\"1426\"\u003e\u003cstrong data-start=\"1240\" data-end=\"1249\"\u003eMedium:\u003c\/strong\u003e \u003cbr data-start=\"1249\" data-end=\"1252\"\u003eRefined and present. Voices sound natural and well-sculpted, with a pleasant fluidity. Acoustic instruments benefit from a credible and well-articulated soundstage.\u003c\/p\u003e\n\u003cp data-start=\"1428\" data-end=\"1625\"\u003e\u003cstrong data-start=\"1428\" data-end=\"1437\"\u003eHighs:\u003c\/strong\u003e\u003cbr data-start=\"1437\" data-end=\"1440\"\u003eDelicate yet present. No harshness, no excess: the highs are silky, well-integrated into the soundscape, and enriched with good detail, ideal for long-term listening.\u003c\/p\u003e\n\u003cp data-start=\"1627\" data-end=\"1833\"\u003e\u003cstrong data-start=\"1627\" data-end=\"1640\"\u003eDynamics:\u003c\/strong\u003e\u003cbr data-start=\"1640\" data-end=\"1643\"\u003eProgressive and natural. Transient response is smooth, with consistent microdynamics. The tube reproduces changes in intensity with musicality and finesse, even at low volumes.\u003c\/p\u003e\n\u003cp data-start=\"1835\" data-end=\"2039\"\u003e\u003cstrong data-start=\"1835\" data-end=\"1850\"\u003eSoundstage:\u003c\/strong\u003e\u003cbr data-start=\"1850\" data-end=\"1853\"\u003eCentral, precise, intimate. The stereo image is stable and uncluttered, with good separation and depth. Not as extensive as that of more powerful tubes, but very realistic and focused.\u003c\/p\u003e\n\u003ch3 data-start=\"2046\" data-end=\"2117\"\u003e🎧 \u003cstrong data-start=\"2053\" data-end=\"2115\"\u003eUse in Push-Pull or Single-Ended Stereo Hi-Fi Amplifiers\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-start=\"2118\" data-end=\"2406\"\u003eExcellent for low-power hi-fi amplifiers, this 1960s RCA 6G6G delivers coherent and immersive sound. Perfect for tube systems with high-efficiency speakers or vintage-style DIY projects. Also recommended for audiophile-oriented single-ended applications.\u003c\/p\u003e\n\u003ch3 data-start=\"2413\" data-end=\"2455\"\u003e🎸 \u003cstrong data-start=\"2420\" data-end=\"2453\"\u003eUse in Music Amplifiers\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-start=\"2456\" data-end=\"2712\"\u003eRarely used in guitar, it can deliver a warm, natural tone in custom circuits. Its response is smooth, well-controlled, with gentle harmonic compression, ideal for clean, expressive sounds in recording environments.\u003c\/p\u003e\n\u003ch3 data-start=\"2719\" data-end=\"2760\"\u003e🎯 \u003cstrong data-start=\"2726\" data-end=\"2758\"\u003eNote for audiophiles and technicians\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-start=\"2761\" data-end=\"3014\"\u003eThis 1960 RCA 6G6G, a JAN military version, combines solid construction with natural musicality. A solid alternative to the more common 6V6, it's a great choice for sophisticated projects or historic restorations of post-war American tube equipment.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eTested with \u003cstrong\u003eAMPLITREX AT-1000\u003c\/strong\u003e Tube tester:\u003cbr\u003eMeasurements taken \u003cstrong\u003eafter 10 minutes\u003c\/strong\u003e of preheating.\u003cbr\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003eTest Conditions:\u003c\/strong\u003e \u003cspan\u003eVa = 180V ; Vg2 = 180V ; Vg = 9V\u003c\/span\u003e\u003cbr\u003e\u003cstrong\u003eAVERAGE 100%:\u003c\/strong\u003e Gm = 2300 ; Ia = 15 mA\u003cbr\u003e\u003cstrong\u003eTest Result:\u003c\/strong\u003e VERY STRONG\u003c\/p\u003e\n\u003cp\u003eValve: Gm = 2500 ; Ia = 18.8 mA\u003cbr\u003e\u003c\/p\u003e\n\u003cdiv\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/div\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e Low. Tested and approved for use in hi-fi and guitar amplifiers.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eOutput Quality:\u003c\/strong\u003e Excellent – Very strong and stable output, no fluctuations.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eShort circuits and GAS:\u003c\/strong\u003e Absent.\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eConditions:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eCondition:\u003c\/strong\u003e \u003cspan\u003eNOS - NIB - New Old Stock, New In Box - Tested and working - Supplied in original box.\u003c\/span\u003e\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eFunctionality:\u003c\/strong\u003e Fully functional.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eCosmetic condition:\u003c\/strong\u003e \u003cspan\u003eExcellent – Excellently preserved lettering, minimal signs of wear. See photos for details.\u003c\/span\u003e\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eManufacturing Code:\u003cspan\u003e\u0026nbsp;\u003c\/span\u003e\u003c\/strong\u003e60-09. - Made by RCA - 9th week of 1960.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca rel=\"noopener\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"RCA","offers":[{"title":"Default Title","offer_id":55049424339292,"sku":"03013I","price":14.95,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_c7d87bef-c466-43f3-95c0-86685d876197.jpg?v=1752936851"},{"product_id":"6g6g-vt-198a-rca-nos-nib-matched-pair-black-plates-square-getter-power-pentode-usa","title":"6G6G = VT-198A = 6G6GT RCA NOS NIB Matched Pair Black Plates Square Getter Power Pentode USA","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003eJAN CRC 6G6G ( VT-198A ) RCA NOS NIB Black Plates Square Getter Power Pentode Matched Pair Tubes MADE IN USA '60\u003c\/strong\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-end=\"560\" data-start=\"258\"\u003eThese \u003cstrong data-end=\"291\" data-start=\"265\"\u003eJAN CRC 6G6G \/ VT-198A\u003c\/strong\u003e , produced by \u003cstrong data-end=\"312\" data-start=\"305\"\u003eRCA\u003c\/strong\u003e in \u003cstrong data-end=\"325\" data-start=\"317\"\u003e1960\u003c\/strong\u003e , are two power amplifier pentodes designed for military applications (JAN = Joint Army Navy). They are in \u003cstrong data-end=\"470\" data-start=\"436\"\u003eNOS (New Old Stock) condition\u003c\/strong\u003e , never used, and come in \u003cstrong data-end=\"557\" data-start=\"510\"\u003etheir original sealed military packaging\u003c\/strong\u003e .\u003c\/p\u003e\n\u003cp data-end=\"947\" data-start=\"562\"\u003eInternally, they feature \u003cstrong data-end=\"611\" data-start=\"595\"\u003eblack plates\u003c\/strong\u003e , a square getter, and a sturdy, well-centered symmetrical structure. The 6G6G is a variant of the 6V6 with slightly different operating characteristics, such as a lower anode voltage, a rounder dynamic response, and a smoother timbre, making it ideal for low-power but highly refined amplifiers.\u003c\/p\u003e\n\u003ch3 data-end=\"1010\" data-start=\"954\"\u003e\u003cstrong data-end=\"1010\" data-start=\"960\"\u003eTimbre characteristics and sound description\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-end=\"1238\" data-start=\"1012\"\u003e\u003cstrong data-end=\"1022\" data-start=\"1012\"\u003eBass:\u003c\/strong\u003e\u003cbr data-end=\"1025\" data-start=\"1022\"\u003eDry and controlled. They offer a quick and clean response, without bloat or excess, restoring the right weight to the instruments without invading the midrange. Excellent for listening in controlled environments.\u003c\/p\u003e\n\u003cp data-end=\"1426\" data-start=\"1240\"\u003e\u003cstrong data-end=\"1249\" data-start=\"1240\"\u003eMedium:\u003c\/strong\u003e \u003cbr data-end=\"1252\" data-start=\"1249\"\u003eRefined and present. Voices sound natural and well-sculpted, with a pleasant fluidity. Acoustic instruments benefit from a credible and well-articulated soundstage.\u003c\/p\u003e\n\u003cp data-end=\"1625\" data-start=\"1428\"\u003e\u003cstrong data-end=\"1437\" data-start=\"1428\"\u003eHighs:\u003c\/strong\u003e\u003cbr data-end=\"1440\" data-start=\"1437\"\u003eDelicate yet present. No harshness, no excess: the highs are silky, well-integrated into the soundscape, and enriched with good detail, ideal for long-term listening.\u003c\/p\u003e\n\u003cp data-end=\"1833\" data-start=\"1627\"\u003e\u003cstrong data-end=\"1640\" data-start=\"1627\"\u003eDynamics:\u003c\/strong\u003e\u003cbr data-end=\"1643\" data-start=\"1640\"\u003eProgressive and natural. Transient response is smooth, with consistent microdynamics. The tube reproduces changes in intensity with musicality and finesse, even at low volumes.\u003c\/p\u003e\n\u003cp data-end=\"2039\" data-start=\"1835\"\u003e\u003cstrong data-end=\"1850\" data-start=\"1835\"\u003eSoundstage:\u003c\/strong\u003e\u003cbr data-end=\"1853\" data-start=\"1850\"\u003eCentral, precise, intimate. The stereo image is stable and uncluttered, with good separation and depth. Not as extensive as that of more powerful tubes, but very realistic and focused.\u003c\/p\u003e\n\u003ch3 data-end=\"2117\" data-start=\"2046\"\u003e🎧 \u003cstrong data-end=\"2115\" data-start=\"2053\"\u003eUse in Push-Pull or Single-Ended Stereo Hi-Fi Amplifiers\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-end=\"2406\" data-start=\"2118\"\u003eExcellent for low-power hi-fi amplifiers, these 1960s RCA 6G6Gs deliver a coherent and engaging musical performance. Perfect for tube systems with high-efficiency speakers or vintage-style DIY projects. Also recommended for audiophile-oriented single-ended applications.\u003c\/p\u003e\n\u003ch3 data-end=\"2455\" data-start=\"2413\"\u003e🎸 \u003cstrong data-end=\"2453\" data-start=\"2420\"\u003eUse in Music Amplifiers\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-end=\"2712\" data-start=\"2456\"\u003eRarely used in guitar, they can deliver a warm, natural tone in custom circuits. Their response is smooth, well-controlled, with gentle harmonic compression, ideal for clean, expressive sounds in recording environments.\u003c\/p\u003e\n\u003ch3 data-end=\"2760\" data-start=\"2719\"\u003e🎯 \u003cstrong data-end=\"2758\" data-start=\"2726\"\u003eNote for audiophiles and technicians\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-end=\"3014\" data-start=\"2761\"\u003eThese 1960 RCA 6G6G, JAN military version, combine solid construction and natural musicality. A valid alternative to the more common 6V6, worth considering for refined projects or historic restorations of post-war American tube equipment.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eTested with \u003cstrong\u003eAMPLITREX AT-1000\u003c\/strong\u003e Tube tester:\u003cbr\u003eMeasurements taken \u003cstrong\u003eafter 10 minutes\u003c\/strong\u003e of preheating.\u003cbr\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003eTest Conditions:\u003c\/strong\u003e \u003cspan\u003eVa = 180V ; Vg2 = 180V ; Vg = 9V\u003c\/span\u003e\u003cbr\u003e\u003cstrong\u003eAVERAGE 100%:\u003c\/strong\u003e Gm = 2300 ; Ia = 15 mA\u003cbr\u003e\u003cstrong\u003eTest Result:\u003c\/strong\u003e VERY STRONG\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eValve 1: Gm = 2500 ; Ia = 17.8 mA\u003cbr\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cmeta charset=\"utf-8\"\u003e Valve 2: Gm = 2500 ; Ia = 17.4 mA\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cdiv\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/div\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e Low. Tested and approved for use in hi-fi and guitar amplifiers.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eOutput Quality:\u003c\/strong\u003e Excellent – Very strong and stable output, no fluctuations.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eShort circuits and GAS:\u003c\/strong\u003e Absent.\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eConditions:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eCondition:\u003c\/strong\u003e \u003cspan\u003eNOS - NIB - New Old Stock, New In Box - Tested and working - Supplied in original box.\u003c\/span\u003e\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eFunctionality:\u003c\/strong\u003e Fully functional.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eCosmetic condition:\u003c\/strong\u003e \u003cspan\u003eExcellent – Excellently preserved lettering, minimal signs of wear. See photos for details.\u003c\/span\u003e\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eManufacturing Code:\u003cspan\u003e\u0026nbsp;\u003c\/span\u003e\u003c\/strong\u003e60-09. - Made by RCA - 9th week of 1960.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"RCA","offers":[{"title":"Default Title","offer_id":55049926443356,"sku":"03014I","price":30.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_61851bd8-3f5b-40e1-a029-a705cd4ed6c1.jpg?v=1752943115"},{"product_id":"6g6g-vt-198a-rca-nos-nib-matched-quad-black-plates-square-getter-power-pentode-usa","title":"6G6G = VT-198A = 6G6GT RCA NOS NIB Matched Quad Black Plates Square Getter Power Pentode USA","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003eJAN CRC 6G6G ( VT-198A ) RCA NOS NIB Black Plates Square Getter Power Pentode Matched Pair Tubes MADE IN USA '60\u003c\/strong\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-end=\"560\" data-start=\"258\"\u003eThese \u003cstrong data-end=\"291\" data-start=\"265\"\u003eJAN CRC 6G6G \/ VT-198A\u003c\/strong\u003e , produced by \u003cstrong data-end=\"312\" data-start=\"305\"\u003eRCA\u003c\/strong\u003e in \u003cstrong data-end=\"325\" data-start=\"317\"\u003e1960\u003c\/strong\u003e , are two power amplifier pentodes designed for military applications (JAN = Joint Army Navy). They are in \u003cstrong data-end=\"470\" data-start=\"436\"\u003eNOS (New Old Stock) condition\u003c\/strong\u003e , never used, and come in \u003cstrong data-end=\"557\" data-start=\"510\"\u003etheir original sealed military packaging\u003c\/strong\u003e .\u003c\/p\u003e\n\u003cp data-end=\"947\" data-start=\"562\"\u003eInternally, they feature \u003cstrong data-end=\"611\" data-start=\"595\"\u003eblack plates\u003c\/strong\u003e , a square getter, and a sturdy, well-centered symmetrical structure. The 6G6G is a variant of the 6V6 with slightly different operating characteristics, such as a lower anode voltage, a rounder dynamic response, and a smoother timbre, making it ideal for low-power but highly refined amplifiers.\u003c\/p\u003e\n\u003ch3 data-end=\"1010\" data-start=\"954\"\u003e\u003cstrong data-end=\"1010\" data-start=\"960\"\u003eTimbre characteristics and sound description\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-end=\"1238\" data-start=\"1012\"\u003e\u003cstrong data-end=\"1022\" data-start=\"1012\"\u003eBass:\u003c\/strong\u003e\u003cbr data-end=\"1025\" data-start=\"1022\"\u003eDry and controlled. They offer a quick and clean response, without bloat or excess, restoring the right weight to the instruments without invading the midrange. Excellent for listening in controlled environments.\u003c\/p\u003e\n\u003cp data-end=\"1426\" data-start=\"1240\"\u003e\u003cstrong data-end=\"1249\" data-start=\"1240\"\u003eMedium:\u003c\/strong\u003e \u003cbr data-end=\"1252\" data-start=\"1249\"\u003eRefined and present. Voices sound natural and well-sculpted, with a pleasant fluidity. Acoustic instruments benefit from a credible and well-articulated soundstage.\u003c\/p\u003e\n\u003cp data-end=\"1625\" data-start=\"1428\"\u003e\u003cstrong data-end=\"1437\" data-start=\"1428\"\u003eHighs:\u003c\/strong\u003e\u003cbr data-end=\"1440\" data-start=\"1437\"\u003eDelicate yet present. No harshness, no excess: the highs are silky, well-integrated into the soundscape, and enriched with good detail, ideal for long-term listening.\u003c\/p\u003e\n\u003cp data-end=\"1833\" data-start=\"1627\"\u003e\u003cstrong data-end=\"1640\" data-start=\"1627\"\u003eDynamics:\u003c\/strong\u003e\u003cbr data-end=\"1643\" data-start=\"1640\"\u003eProgressive and natural. Transient response is smooth, with consistent microdynamics. The tube reproduces changes in intensity with musicality and finesse, even at low volumes.\u003c\/p\u003e\n\u003cp data-end=\"2039\" data-start=\"1835\"\u003e\u003cstrong data-end=\"1850\" data-start=\"1835\"\u003eSoundstage:\u003c\/strong\u003e\u003cbr data-end=\"1853\" data-start=\"1850\"\u003eCentral, precise, intimate. The stereo image is stable and uncluttered, with good separation and depth. Not as extensive as that of more powerful tubes, but very realistic and focused.\u003c\/p\u003e\n\u003ch3 data-end=\"2117\" data-start=\"2046\"\u003e🎧 \u003cstrong data-end=\"2115\" data-start=\"2053\"\u003eUse in Push-Pull or Single-Ended Stereo Hi-Fi Amplifiers\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-end=\"2406\" data-start=\"2118\"\u003eExcellent for low-power hi-fi amplifiers, these 1960s RCA 6G6Gs deliver a coherent and engaging musical performance. Perfect for tube systems with high-efficiency speakers or vintage-style DIY projects. Also recommended for audiophile-oriented single-ended applications.\u003c\/p\u003e\n\u003ch3 data-end=\"2455\" data-start=\"2413\"\u003e🎸 \u003cstrong data-end=\"2453\" data-start=\"2420\"\u003eUse in Music Amplifiers\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-end=\"2712\" data-start=\"2456\"\u003eRarely used in guitar, they can deliver a warm, natural tone in custom circuits. Their response is smooth, well-controlled, with gentle harmonic compression, ideal for clean, expressive sounds in recording environments.\u003c\/p\u003e\n\u003ch3 data-end=\"2760\" data-start=\"2719\"\u003e🎯 \u003cstrong data-end=\"2758\" data-start=\"2726\"\u003eNote for audiophiles and technicians\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-end=\"3014\" data-start=\"2761\"\u003eThese 1960 RCA 6G6G, JAN military version, combine solid construction and natural musicality. A valid alternative to the more common 6V6, worth considering for refined projects or historic restorations of post-war American tube equipment.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eTested with \u003cstrong\u003eAMPLITREX AT-1000\u003c\/strong\u003e Tube tester:\u003cbr\u003eMeasurements taken \u003cstrong\u003eafter 10 minutes\u003c\/strong\u003e of preheating.\u003cbr\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003eTest Conditions:\u003c\/strong\u003e \u003cspan\u003eVa = 180V ; Vg2 = 180V ; Vg = 9V\u003c\/span\u003e\u003cbr\u003e\u003cstrong\u003eAVERAGE 100%:\u003c\/strong\u003e Gm = 2300 ; Ia = 15 mA\u003cbr\u003e\u003cstrong\u003eTest Result:\u003c\/strong\u003e VERY STRONG\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eValve 1: Gm = 2400 ; Ia = 15.6 mA\u003cbr\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cmeta charset=\"utf-8\"\u003e Valve 2: Gm =\u003cmeta charset=\"utf-8\"\u003e 2400 ; Ia = 15.8 mA\u003c\/li\u003e\n\u003cli\u003eValve 3: Gm =\u003cmeta charset=\"utf-8\"\u003e 2400 ; Ia = 15.0 mA\u003cbr\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cmeta charset=\"utf-8\"\u003e Valve 4: Gm =\u003cmeta charset=\"utf-8\"\u003e 2400 ; Ia = 15.2 mA\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cdiv\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/div\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e Low. Tested and approved for use in hi-fi and guitar amplifiers.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eOutput Quality:\u003c\/strong\u003e Excellent – Very strong and stable output, no fluctuations.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eShort circuits and GAS:\u003c\/strong\u003e Absent.\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eConditions:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eCondition:\u003c\/strong\u003e \u003cspan\u003eNOS - NIB - New Old Stock, New In Box - Tested and working - Supplied in original box.\u003c\/span\u003e\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eFunctionality:\u003c\/strong\u003e Fully functional.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eCosmetic condition:\u003c\/strong\u003e \u003cspan\u003eExcellent – Excellently preserved lettering, minimal signs of wear. See photos for details.\u003c\/span\u003e\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eManufacturing Code:\u003cspan\u003e\u0026nbsp;\u003c\/span\u003e\u003c\/strong\u003e60-09. - Made by RCA - 9th week of 1960.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"RCA","offers":[{"title":"Default Title","offer_id":55050086318428,"sku":"03015I","price":61.8,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_2a937909-5540-4f69-8693-97381053f7c6.jpg?v=1753085167"},{"product_id":"6ca7-el34-philips-eindhoven-metal-base-one-piece-disc-getter-matched-pair-tubes-holland","title":"6CA7 EL34 AMPEREX by PHILIPS Eindhoven Metal Base '55 One-Piece Disc Getter Matched Pair Amplitrex Tested Curves Included","description":"\u003cp\u003e\u003cstrong\u003e6CA7 ( EL34 ) AMPEREX by PHILIPS Eindhoven Metal Base One piece Disc Getter Matched Pair Tubes Made in Holland '55\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003ch3\u003e \u003cstrong\u003eDescription:\u003c\/strong\u003e\n\u003c\/h3\u003e\n\n\u003cp data-end=\"552\" data-start=\"208\"\u003e The PHILIPS Eindhoven \u003cstrong data-end=\"261\" data-start=\"243\"\u003emetal-base\u003c\/strong\u003e 6CA7 (EL34) tubes, produced in Holland in 1955 for AMPEREX, represent one of the rarest and most prestigious versions of this iconic power tube. These are \u003cstrong data-end=\"420\" data-start=\"405\"\u003efirst-series\u003c\/strong\u003e examples, with \u003cstrong data-end=\"454\" data-start=\"426\"\u003eone-piece disc getters\u003c\/strong\u003e and extremely high-quality internal construction, made in the Philips factory in Eindhoven.\u003c\/p\u003e\n\n \u003cp data-end=\"936\" data-start=\"554\"\u003eThis \u003cstrong data-end=\"584\" data-start=\"568\"\u003ematched\u003c\/strong\u003e pair, although used, has been tested with \u003cstrong data-end=\"645\" data-start=\"635\"\u003eSTRONG\u003c\/strong\u003e results, demonstrating full efficiency and still guaranteeing a long operating life. The metal base, a trademark of early European production, is considered by many audiophiles and collectors to be the maximum expression of the 6CA7\/EL34 for sonic transparency, robustness and historical appeal.\u003c\/p\u003e\n\n\u003ch3 data-end=\"985\" data-start=\"938\"\u003e Timbre characteristics and sound output\u003c\/h3\u003e\n\n\u003cul\u003e\n\n\u003cli data-end=\"1105\" data-start=\"988\"\u003e\n\n \u003cstrong data-end=\"998\" data-start=\"988\"\u003eBass:\u003c\/strong\u003e deep, fast and rock-solid, with an immediate response that gives authority and control to the low range.\u003c\/li\u003e\n\n\u003cli data-end=\"1243\" data-start=\"1108\"\u003e\n\n \u003cstrong data-end=\"1117\" data-start=\"1108\"\u003eMids:\u003c\/strong\u003e Transparent and refined, with a natural balance that delivers vocals and acoustic instruments in all their authenticity.\u003c\/li\u003e\n\n\u003cli data-end=\"1345\" data-start=\"1246\"\u003e\n\n \u003cstrong data-end=\"1255\" data-start=\"1246\"\u003eHighs:\u003c\/strong\u003e airy, bright and never aggressive, with a detail that enriches without weighing down.\u003c\/li\u003e\n\n\u003cli data-end=\"1472\" data-start=\"1348\"\u003e \n\u003cstrong data-end=\"1361\" data-start=\"1348\"\u003eDynamics:\u003c\/strong\u003e explosive and coherent, capable of faithfully following the most complex variations without loss of definition.\u003c\/li\u003e\n\n\u003cli data-end=\"1571\" data-start=\"1475\"\u003e\n\n \u003cstrong data-end=\"1490\" data-start=\"1475\"\u003eSoundstage:\u003c\/strong\u003e wide and three-dimensional, with stable imaging and great perspective depth.\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003ch3 data-end=\"1594\" data-start=\"1573\"\u003e 🎧 Hi-Fi use\u003c\/h3\u003e\n\n\u003cp data-end=\"1805\" data-start=\"1595\"\u003e Perfect for reference tube amplifiers (Quad II, Leak, Marantz, etc.), these Philips Metal Bases bring out the musicality of the EL34 series to the fullest, combining unmatched refinement and power.\u003c\/p\u003e\n\n\u003ch3 data-end=\"1845\" data-start=\"1807\"\u003e 🎸 Use in Music Amplifiers\u003c\/h3\u003e\n\n\u003cp data-end=\"2019\" data-start=\"1846\"\u003e In the guitar and musical fields, they guarantee a full-bodied and dynamic sound, with rich harmonics and a creamy saturation that made the first European EL34s legendary.\u003c\/p\u003e\n\n\u003ch3 data-end=\"2064\" data-start=\"2021\"\u003e 🎯 Note for audiophiles and collectors\u003c\/h3\u003e\n\n \u003cp data-end=\"2444\" data-start=\"2065\"\u003ePhilips Eindhoven Metal Bases are among the \u003cstrong data-end=\"2138\" data-start=\"2109\"\u003emost sought-after and rare EL34s\u003c\/strong\u003e , considered by many to be the \"definitive version\" of this tube. This matched pair— \u003cstrong data-end=\"2255\" data-start=\"2227\"\u003eused but STRONG tested\u003c\/strong\u003e —represents an unmissable opportunity for anyone wishing to own a piece of 1950s European tube manufacturing history, combining collectible value with exceptional sound quality.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch3\u003e \u003cstrong\u003eTest Results:\u003c\/strong\u003e\n\u003c\/h3\u003e\n\n\u003cp\u003e Valve tested on \u003cstrong\u003eAMPLITREX AT-1000\u003c\/strong\u003e Tube Tester:\u003c\/p\u003e\n\n\u003cul\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eTest Conditions:\u003c\/strong\u003e \u003cspan\u003eVa = 500V; Vg2 = 450; Vg = -36.5V\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eAverage 100%:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eGm = 6.5 ; Ia = 50 mA\u003c\/li\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eTest Result:\u003c\/strong\u003e STRONG\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003eValve 1:\u003c\/strong\u003e Gm = 5.8 ; Ia = 36 mA\u003c\/p\u003e\n\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003eValve 2:\u003c\/strong\u003e Gm = 5.9 ; Ia = 35 mA\u003c\/p\u003e\n\n\u003cdiv\u003e \u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\n\u003c\/div\u003e\n\n\u003cul\u003e\n\n \u003cli\u003e\u003cspan\u003e\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e Standard. Tested and approved for use in hi-fi and guitar amplifiers.\u003c\/span\u003e\u003c\/li\u003e\n\n\u003cli\u003e \u003cspan\u003e\u003cstrong\u003eOutput Quality:\u003c\/strong\u003e Excellent – ​​Very strong and stable output, no fluctuations.\u003c\/span\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e \u003cspan\u003e\u003cstrong\u003eShort circuits and GAS:\u003c\/strong\u003e Absent.\u003c\/span\u003e\n\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch3\u003e \u003cstrong\u003eConditions:\u003c\/strong\u003e\n\u003c\/h3\u003e\n\n\u003cul\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eConditions:\u003cspan\u003e \u003c\/span\u003e\u003c\/strong\u003eVintage Tubes - Tested and in perfect working order. Comes in our custom box for optimal protection.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eFunctionality:\u003c\/strong\u003e Fully functional.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eAesthetic condition:\u003c\/strong\u003e \u003cspan\u003eFair – Writing almost completely faded, with obvious signs of wear on the metal base. See photos for details.\u003c\/span\u003e\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\n\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cp\u003e \u003cstrong\u003eManufacturing Code:\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n\n\u003cli\u003e SY0 55F - \u003cstrong data-end=\"105\" data-start=\"98\"\u003eSY0\u003c\/strong\u003e\u003cmeta charset=\"utf-8\"\u003e → Series code (EL34 metal base \u003cem data-end=\"146\" data-start=\"123\"\u003eone-piece disc getter\u003c\/em\u003e ), \u003cstrong\u003e5\u003c\/strong\u003e  \u003cmeta charset=\"utf-8\"\u003e→\u003cmeta charset=\"utf-8\"\u003e Philips Eindhoven, \u003cstrong data-start=\"59\" data-end=\"80\"\u003e5F\u003c\/strong\u003e → June 1955 ( \u003cem data-is-only-node=\"\" data-end=\"169\" data-start=\"166\"\u003eF\u003c\/em\u003e = 6th month).\u003c\/li\u003e\n\n\u003cli\u003e SY0 56L -\u003cmeta charset=\"utf-8\"\u003e \u003cstrong data-end=\"105\" data-start=\"98\"\u003eSY0\u003c\/strong\u003e\u003cmeta charset=\"utf-8\"\u003e → Series code (EL34 metal base \u003cem data-end=\"146\" data-start=\"123\"\u003eone-piece disc getter\u003c\/em\u003e ), \u003cstrong\u003e5\u003c\/strong\u003e\u003cmeta charset=\"utf-8\"\u003e →\u003cmeta charset=\"utf-8\"\u003e Philips Eindhoven, \u003cstrong data-start=\"59\" data-end=\"80\"\u003e6L\u003c\/strong\u003e →\u003cmeta charset=\"utf-8\"\u003e December 1956 ( \u003cem data-end=\"268\" data-start=\"265\"\u003eL\u003c\/em\u003e = 12th month)\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e \u003ca href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" title=\"Why our tubes are different – ​​the VTT protocol that improves sound, reliability and durability\" rel=\"noopener\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"AMPEREX","offers":[{"title":"Default Title","offer_id":55471230714204,"sku":"03109","price":849.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/3_5730e83e-fc43-4842-be5e-febf418793e7.jpg?v=1757776931"},{"product_id":"6aq5-a-el90-rca-black-plate-round-getter-made-in-usa-61","title":"6AQ5A ( EL90 ) RCA NOS Black Plate Halo Getter Made in USA ’61","description":"\u003cp\u003e\u003cstrong\u003e6AQ5A ( EL90 ) RCA NOS Black Plate Halo Getter Made in USA '61\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-start=\"317\" data-end=\"831\"\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cmeta charset=\"utf-8\"\u003e The \u003cstrong data-end=\"240\" data-start=\"220\"\u003eRCA 6AQ5A (EL90)\u003c\/strong\u003e , with \u003cstrong data-end=\"262\" data-start=\"246\"\u003eblack plates\u003c\/strong\u003e and \u003cstrong data-end=\"280\" data-start=\"265\"\u003ehalo getter\u003c\/strong\u003e , produced in the United States in 1961, is a miniature power tube highly prized for its warm musicality and solid construction. In this \u003cstrong data-end=\"471\" data-start=\"448\"\u003eNOS (New Old Stock)\u003c\/strong\u003e version, it represents an authentic example of the great RCA tradition: reliability, tonal balance and a sound with an unmistakable character.\u003cbr\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli data-end=\"732\" data-start=\"653\"\u003e\u003cstrong data-end=\"662\" data-start=\"653\"\u003eBass\u003c\/strong\u003e : compact, fast and well controlled, with a solid and precise base.\u003c\/li\u003e\n\u003cli data-end=\"843\" data-start=\"735\"\u003e\u003cstrong data-end=\"743\" data-start=\"735\"\u003eMids\u003c\/strong\u003e : Warm and natural, with a rich texture that gives body and realism to vocals and acoustic instruments.\u003c\/li\u003e\n\u003cli data-end=\"923\" data-start=\"846\"\u003e\u003cstrong data-end=\"854\" data-start=\"846\"\u003eHighs\u003c\/strong\u003e : sweet and velvety, with balanced and never aggressive brilliance.\u003c\/li\u003e\n\u003cli data-end=\"1015\" data-start=\"926\"\u003e\u003cstrong data-end=\"938\" data-start=\"926\"\u003eDynamics\u003c\/strong\u003e : lively and well-proportioned, with a fluid response even at high volumes.\u003c\/li\u003e\n\u003cli data-end=\"1104\" data-start=\"1018\"\u003e\u003cstrong data-end=\"1032\" data-start=\"1018\"\u003eSoundstage\u003c\/strong\u003e : Coherent and stable, with good depth and natural sound imaging.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"2327\" data-end=\"2387\"\u003e🎧\u003cspan\u003e\u0026nbsp;\u003c\/span\u003e\u003cstrong data-start=\"2330\" data-end=\"2387\"\u003eUse in Headphone Amplifiers and Hi-Fi Driver Stages\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"2389\" data-end=\"2712\"\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cmeta charset=\"utf-8\"\u003e Perfect for small hi-fi amplifiers and vintage systems, the 6AQ5A RCA offers transparent and musical performance, faithful to the original design and ideal for those seeking authenticity and naturalness in listening.\u003cbr\u003e\u003c\/p\u003e\n\u003cp data-start=\"2714\" data-end=\"2762\"\u003e🎸\u003cspan\u003e\u0026nbsp;\u003c\/span\u003e\u003cstrong data-start=\"2717\" data-end=\"2762\"\u003eUse in Guitar and Bass Amplifiers\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"2764\" data-end=\"3016\"\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cmeta charset=\"utf-8\"\u003eAlso widely used in small guitar amps from the 50s and 60s, this RCA delivers a creamy, warm, harmonic-rich sound, perfect for blues and classic rock.\u003cbr\u003e\u003c\/p\u003e\n\u003cp data-start=\"3018\" data-end=\"3244\"\u003e🎯\u003cspan\u003e\u0026nbsp;\u003c\/span\u003e\u003cstrong data-start=\"3021\" data-end=\"3053\"\u003eNote for audiophiles and technicians\u003c\/strong\u003e\u003cbr data-start=\"3053\" data-end=\"3056\"\u003e\u003cmeta charset=\"utf-8\"\u003e The \u003cstrong data-end=\"1643\" data-start=\"1597\"\u003e1961 6AQ5A RCA Black Plate Halo Getter\u003c\/strong\u003e is a rare and sought-after NOS tube, ideal for philological restorations, collections, and high-end audio applications. A true piece of American sonic tradition.\u003cbr\u003e\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eValve tested on \u003cstrong\u003eAMPLITREX AT-1000\u003c\/strong\u003e Tube Tester:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eTest Conditions:\u003c\/strong\u003e \u003cspan\u003eVa = 250V ; Vg2 = 250V ; Vg = -12.5V\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eAverage 100%:\u003c\/strong\u003e\u003cspan\u003e\u0026nbsp;\u003c\/span\u003eGm = 4.1 ; Ia = 45 mA\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eTest Result:\u003c\/strong\u003e VERY STRONG\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eValve:\u003c\/strong\u003e\u003cspan\u003e\u0026nbsp;\u003c\/span\u003eGm = 4.3 ; Ia = 46 mA\u003c\/p\u003e\n\u003cdiv\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/div\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e Low. Tested and approved for use in hi-fi and guitar amplifiers.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eOutput Quality:\u003c\/strong\u003e Excellent – Very strong and stable output, no fluctuations.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eShort circuits and GAS:\u003c\/strong\u003e Absent.\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eConditions:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eCondition:\u003c\/strong\u003e NOS - New Old Stock - Tested and working - Supplied in our custom box for optimal protection.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eFunctionality:\u003c\/strong\u003e Fully functional.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eCosmetic condition:\u003c\/strong\u003e Excellent – Excellently preserved lettering, minimal signs of wear. See photos for details.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eManufacturing Code:\u003c\/strong\u003e MH → two-letter code → production June 1961\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca rel=\"noopener\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"RCA","offers":[{"title":"Default Title","offer_id":55550294131036,"sku":"03154","price":9.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_f50d6455-2cbd-49f4-b29d-bca4d8fdb860.jpg?v=1758699109"},{"product_id":"6aq5-a-el90-rca-nos-black-plate-halo-getter-made-in-usa-59","title":"6AQ5 A ( EL90 ) RCA NOS Black Plate Halo Getter Made in USA '59","description":"\u003cp\u003e\u003cstrong\u003e6AQ5A ( EL90 ) RCA NOS Black Plate Halo Getter Made in USA '59\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-start=\"317\" data-end=\"831\"\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cmeta charset=\"utf-8\"\u003e The \u003cstrong data-end=\"240\" data-start=\"220\"\u003eRCA 6AQ5A (EL90)\u003c\/strong\u003e , with \u003cstrong data-end=\"262\" data-start=\"246\"\u003eblack plates\u003c\/strong\u003e and \u003cstrong data-end=\"280\" data-start=\"265\"\u003ehalo getter\u003c\/strong\u003e , produced in the United States in 1959, is a miniature power tube highly prized for its warm musicality and solid construction. In this \u003cstrong data-end=\"471\" data-start=\"448\"\u003eNOS (New Old Stock)\u003c\/strong\u003e version, it represents an authentic example of the great RCA tradition: reliability, tonal balance and a sound with an unmistakable character.\u003cbr\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli data-end=\"732\" data-start=\"653\"\u003e\u003cstrong data-end=\"662\" data-start=\"653\"\u003eBass\u003c\/strong\u003e : compact, fast and well controlled, with a solid and precise base.\u003c\/li\u003e\n\u003cli data-end=\"843\" data-start=\"735\"\u003e\u003cstrong data-end=\"743\" data-start=\"735\"\u003eMids\u003c\/strong\u003e : Warm and natural, with a rich texture that gives body and realism to vocals and acoustic instruments.\u003c\/li\u003e\n\u003cli data-end=\"923\" data-start=\"846\"\u003e\u003cstrong data-end=\"854\" data-start=\"846\"\u003eHighs\u003c\/strong\u003e : sweet and velvety, with balanced and never aggressive brilliance.\u003c\/li\u003e\n\u003cli data-end=\"1015\" data-start=\"926\"\u003e\u003cstrong data-end=\"938\" data-start=\"926\"\u003eDynamics\u003c\/strong\u003e : lively and well-proportioned, with a fluid response even at high volumes.\u003c\/li\u003e\n\u003cli data-end=\"1104\" data-start=\"1018\"\u003e\u003cstrong data-end=\"1032\" data-start=\"1018\"\u003eSoundstage\u003c\/strong\u003e : Coherent and stable, with good depth and natural sound imaging.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"2327\" data-end=\"2387\"\u003e🎧\u003cspan\u003e\u0026nbsp;\u003c\/span\u003e\u003cstrong data-start=\"2330\" data-end=\"2387\"\u003eUse in Headphone Amplifiers and Hi-Fi Driver Stages\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"2389\" data-end=\"2712\"\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cmeta charset=\"utf-8\"\u003e Perfect for small hi-fi amplifiers and vintage systems, the 6AQ5A RCA offers transparent and musical performance, faithful to the original design and ideal for those seeking authenticity and naturalness in listening.\u003cbr\u003e\u003c\/p\u003e\n\u003cp data-start=\"2714\" data-end=\"2762\"\u003e🎸\u003cspan\u003e\u0026nbsp;\u003c\/span\u003e\u003cstrong data-start=\"2717\" data-end=\"2762\"\u003eUse in Guitar and Bass Amplifiers\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"2764\" data-end=\"3016\"\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cmeta charset=\"utf-8\"\u003eAlso widely used in small guitar amps from the 50s and 60s, this RCA delivers a creamy, warm, harmonic-rich sound, perfect for blues and classic rock.\u003cbr\u003e\u003c\/p\u003e\n\u003cp data-start=\"3018\" data-end=\"3244\"\u003e🎯\u003cspan\u003e\u0026nbsp;\u003c\/span\u003e\u003cstrong data-start=\"3021\" data-end=\"3053\"\u003eNote for audiophiles and technicians\u003c\/strong\u003e\u003cbr data-start=\"3053\" data-end=\"3056\"\u003e\u003cmeta charset=\"utf-8\"\u003e The \u003cstrong data-end=\"1643\" data-start=\"1597\"\u003e1959\u0026nbsp;6AQ5A RCA Black Plate Halo Getter\u003c\/strong\u003e is a rare and sought-after NOS tube, ideal for philological restorations, collections, and high-end audio applications. A true piece of American sonic tradition.\u003cbr\u003e\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eValve tested on \u003cstrong\u003eAMPLITREX AT-1000\u003c\/strong\u003e Tube Tester:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eTest Conditions:\u003c\/strong\u003e \u003cspan\u003eVa = 250V ; Vg2 = 250V ; Vg = -12.5V\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eAverage 100%:\u003c\/strong\u003e\u003cspan\u003e\u0026nbsp;\u003c\/span\u003eGm = 4.1 ; Ia = 45 mA\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eTest Result:\u003c\/strong\u003e VERY STRONG\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eValve:\u003c\/strong\u003e\u003cspan\u003e\u0026nbsp;\u003c\/span\u003eGm = 4.3 ; Ia = 46 mA\u003c\/p\u003e\n\u003cdiv\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/div\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e Low. Tested and approved for use in hi-fi and guitar amplifiers.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eOutput Quality:\u003c\/strong\u003e Excellent – Very strong and stable output, no fluctuations.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eShort circuits and GAS:\u003c\/strong\u003e Absent.\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eConditions:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eCondition:\u003c\/strong\u003e NOS - New Old Stock - Tested and working - Supplied in our custom box for optimal protection.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eFunctionality:\u003c\/strong\u003e Fully functional.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eCosmetic condition:\u003c\/strong\u003e Excellent – Excellently preserved lettering, minimal signs of wear. See photos for details.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eManufacturing Code:\u003c\/strong\u003e\u0026nbsp;LI → two-letter code → production\u0026nbsp;May 1959\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca rel=\"noopener\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"RCA","offers":[{"title":"Default Title","offer_id":55550433460572,"sku":"03155","price":9.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_14cad39b-e7f0-4a21-af5f-e1e9697f9c75.jpg?v=1758699791"},{"product_id":"jj-kt77-signature-quad-matched-24h-burn-in-amplitrex-curve-tested-tubes","title":"KT77 EL34 JJ Signature Matched Quad 24h Burn-in Amplitrex Curve Tested Tubes","description":"\u003ch3 data-end=\"303\" data-start=\"205\"\u003e\u003cstrong\u003eKT77 EL34 JJ Signature Matched Quad - NEW - 24h Burn-in - Amplitrex Curve Tested Tubes\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cstrong\u003eMADE IN SLOVAKIA\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-end=\"424\" data-start=\"304\"\u003e\u003cmeta charset=\"utf-8\"\u003eThe \u003cspan class=\"s1\"\u003e\u003cb\u003eKT77\u003c\/b\u003e\u003c\/span\u003e is a \u003cspan class=\"s1\"\u003e\u003cb\u003ebeam power pentode with an octal base\u003c\/b\u003e\u003c\/span\u003e, usable in the vast majority of amplifiers designed for \u003cspan class=\"s1\"\u003e\u003cb\u003eEL34\u003c\/b\u003e\u003c\/span\u003e. Compared to the EL34 and E34L, it offers \u003cspan class=\"s1\"\u003e\u003cb\u003egreater available power, more authoritative bass, and superior headroom\u003c\/b\u003e\u003c\/span\u003e, while maintaining a high level of detail and a balanced tonal rendition.\u003c\/p\u003e\n\u003cp data-end=\"424\" data-start=\"304\"\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cstrong data-end=\"412\" data-start=\"388\"\u003eThe KT77 JJ Signature\u003c\/strong\u003e tubes embody all the good qualities of the KT77 JJ - \u003cstrong\u003emusicality, transparency, and extended response\u003c\/strong\u003e - and elevate them to a higher level.\u003cbr data-end=\"533\" data-start=\"530\"\u003eThanks to a \u003cstrong data-end=\"564\" data-start=\"543\"\u003e24-hour burn-in\u003c\/strong\u003e and \u003cstrong data-end=\"617\" data-start=\"570\"\u003ematching based on real Amplitrex dynamic curves\u003c\/strong\u003e, the sound gains \u003cstrong\u003egreater coherence, precision, and depth.\u003c\/strong\u003e\u003cbr data-end=\"681\" data-start=\"678\"\u003eThe \u003cstrong\u003ebass\u003c\/strong\u003e is tight and articulate, the \u003cstrong\u003emids\u003c\/strong\u003e are rich in harmonics, and the \u003cstrong\u003etreble\u003c\/strong\u003e is open and refined.\u003cbr data-end=\"787\" data-start=\"784\"\u003eEach quad is individually formed based on real dynamic measurements on Amplitrex and accompanied by an \u003cstrong data-end=\"874\" data-start=\"849\"\u003eindividual test card\u003c\/strong\u003e with the actual curve graph.\u003cbr data-end=\"911\" data-start=\"908\"\u003e\u003cstrong data-end=\"964\" data-start=\"911\"\u003eNo generic preprints, no invented data\u003c\/strong\u003e: each curve is unique, just like each tube.\u003c\/p\u003e\n\u003chr data-end=\"813\" data-start=\"810\"\u003e\n\u003ch3 data-end=\"890\" data-start=\"815\"\u003eSignature Selection Process – Advanced Technique and Total Transparency\u003c\/h3\u003e\n\u003cul\u003e\n\n\u003cli data-end=\"1621\" data-start=\"1520\"\u003e24-hour \u003cstrong data-end=\"1549\" data-start=\"1533\"\u003ereal burn-in\u003c\/strong\u003e on a Maxi-Burn station, to stabilize electrical characteristics\u003c\/li\u003e\n\n\u003cli data-end=\"1734\" data-start=\"1624\"\u003eTest on \u003cstrong data-end=\"1655\" data-start=\"1634\"\u003eAmplitrex AT-1000\u003c\/strong\u003e at real operating voltages, with dynamic matching and symmetry verification\u003c\/li\u003e\n\n\u003cli data-end=\"1823\" data-start=\"1737\"\u003eComplete analysis of \u003cstrong data-end=\"1787\" data-start=\"1762\"\u003echaracteristic curves\u003c\/strong\u003e, not just static values (Gm, Ip)\u003c\/li\u003e\n\n\u003cli data-end=\"1902\" data-start=\"1826\"\u003eTechnical appendix with \u003cstrong data-end=\"1873\" data-start=\"1849\"\u003eprinted real curves\u003c\/strong\u003e and sealed numbered envelope\u003cbr\u003e\n\n\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003chr data-end=\"1599\" data-start=\"1596\"\u003e\n\u003ch3 data-end=\"1621\" data-start=\"1601\"\u003eSonic Character\u003c\/h3\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003eBass:\u003c\/strong\u003e tight and defined, with excellent control and natural rhythm\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eMids:\u003c\/strong\u003e balanced, open, and rich in musical harmonics\u003cbr data-start=\"139\" data-end=\"142\"\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eTreble: \u003c\/strong\u003eclear and airy, never harsh\u003cbr data-start=\"179\" data-end=\"182\"\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eDynamics:\u003c\/strong\u003e prompt, proportionate, and engaging\u003cbr data-start=\"228\" data-end=\"231\"\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eSoundstage:\u003c\/strong\u003e wide, precise, and well-focused\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp data-start=\"2372\" data-end=\"2567\"\u003e🎧 \u003cmeta charset=\"utf-8\"\u003e\u003cem\u003eIdeal for Hi-Fi systems with a transparent and musical character (Leak, Dynaco, Audio Research)\u003c\/em\u003e\u003cbr data-start=\"2466\" data-end=\"2469\"\u003e🎸 \u003cmeta charset=\"utf-8\"\u003e\u003cem\u003ePerfect for guitar amplifiers with balanced tone and controlled dynamic response.\u003c\/em\u003e\u003c\/p\u003e\n\u003chr data-end=\"1599\" data-start=\"1596\"\u003e\n\u003ch3\u003eTest Specifications\u003c\/h3\u003e\n\u003cp data-end=\"619\" data-start=\"434\"\u003eTubes tested on \u003cstrong data-end=\"486\" data-start=\"453\"\u003eAmplitrex AT-1000 Tube Tester\u003c\/strong\u003e at real operating voltages, with measurements taken after 10 minutes of warm-up.\u003c\/p\u003e\n\u003cp data-end=\"653\" data-start=\"621\"\u003e\u003cstrong data-end=\"651\" data-start=\"621\"\u003eAdditional tests performed:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli data-end=\"727\" data-start=\"656\"\u003e\n\n\u003cstrong data-end=\"674\" data-start=\"656\"\u003eMicrophonics:\u003c\/strong\u003e compliant with hi-fi and musical instrument standards.\u003c\/li\u003e\n\n\u003cli data-end=\"809\" data-start=\"730\"\u003e\n\n\u003cstrong data-end=\"757\" data-start=\"730\"\u003eEmission Quality:\u003c\/strong\u003e excellent – stable, strong, and regular emission.\u003c\/li\u003e\n\n\u003cli data-end=\"847\" data-start=\"812\"\u003e\n\n\u003cstrong data-end=\"836\" data-start=\"812\"\u003eShort Circuits \/ GAS:\u003c\/strong\u003e absent.\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp data-end=\"1039\" data-start=\"849\"\u003e\u003cspan data-end=\"880\" data-start=\"859\"\u003eEach\u003c\/span\u003e\u003cstrong data-end=\"880\" data-start=\"859\"\u003e Signature quad\u003c\/strong\u003e is individually formed based on real dynamic measurements on Amplitrex, designed for those who seek the sonic essence, not just a numerical reading, but a real evaluation of electrical behavior.\u003c\/p\u003e\n\u003chr data-end=\"1599\" data-start=\"1596\"\u003e\n\u003ch3\u003eConditions\u003c\/h3\u003e\n\u003cul\u003e\n\n\u003cli\u003eSupplied in our custom box for optimal protection.\u003c\/li\u003e\n\n\u003cli\u003eFunctionality: impeccable\u003c\/li\u003e\n\n\u003cli\u003e\n\u003cstrong\u003eFactory new\u003c\/strong\u003e tubes, tested and perfectly functional. \u003cstrong\u003e24-month legal warranty\u003c\/strong\u003e (consumers, Legislative Decree 206\/2005). \u003cstrong\u003eB2B: Articles 1490 et seq. of the Civil Code apply.\u003c\/strong\u003e\u003cbr\u003e\u003cstrong\u003eReturns for sound preferences\/tube rolling not accepted. 14-day right of withdrawal\u003c\/strong\u003e only with \u003cstrong\u003eintact\u003c\/strong\u003e seal and \u003cstrong\u003eunused\u003c\/strong\u003e tube. The warranty covers only \u003cstrong\u003eoriginal conformity defects\u003c\/strong\u003e; it excludes \u003cstrong\u003ewear and tear\u003c\/strong\u003e, \u003cstrong\u003eimproper use\u003c\/strong\u003e, and \u003cstrong\u003etampering\u003c\/strong\u003e.\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003ch3\u003eAdditional Information\u003c\/h3\u003e\n\u003cp\u003eJJ tubes may exhibit \u003cstrong\u003eslight variations in glass envelope height\u003c\/strong\u003e, with no impact on performance.\u003c\/p\u003e\n\u003chr\u003e\n\u003cp\u003e\u003cspan style=\"color: rgb(43, 0, 255);\"\u003e\u003cstrong\u003eFAQ - Frequently Asked Questions:\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eQuestion:\u003c\/strong\u003e What do dynamic matching, full symmetry verification, and active curve analysis mean? Aren't the test data on the label enough?\u003cbr\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eAnswer:\u003c\/strong\u003e Static data on the label tells us \"how much\" a tube works. The actual curve shows \"how\" it works. It's a bit like knowing a car can go 200 km\/h... but without knowing how it accelerates, brakes, or handles. Dynamic curves allow us to select four tubes that \"drive\" in the same way during the musical journey.\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eQuestion: \u003c\/strong\u003eBut sonically, what really changes compared to standard matching?\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eAnswer:\u003c\/strong\u003e The sound gains in precision, detail, and stability. The bass is more controlled, the stereo image is more focused, and vocals are more natural. Dynamic matching reduces dissonances between tubes and transforms the listening experience: more musical, more credible, more engaging.\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eQuestion:\u003c\/strong\u003e After installation, do they immediately sound their best? Or do they need a break-in?\u003cbr\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eAnswer:\u003c\/strong\u003e Immediately after installation, they sound good, but the best comes with time. Already after 50 hours, the bass becomes tighter, and around 100 hours, the tonal balance stabilizes. Break-in is part of the process that makes the sound more natural and engaging.\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eQuestion:\u003c\/strong\u003e What is the 24-hour burn-in? And how does it compare to break-in?\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eAnswer:\u003c\/strong\u003e No, it's a different technical phase: before being tested, the tubes remain powered for 24 hours under controlled conditions. This serves to stabilize internal parameters and eliminate unstable units. Thus, the customer receives only reliable, already \"settled\" tubes.\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e🔍 Discover what we truly think: \u003ca rel=\"noopener\" title=\"Guida completa alla valvola 6550 JJ\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/guida-completa-alla-valvola-6550-jj\" target=\"_blank\"\u003eread our complete guide to the 6550 JJ.\u003c\/a\u003e\u003c\/p\u003e","brand":"JJ ELECTRONICS","offers":[{"title":"Default Title","offer_id":55658321707356,"sku":"03192","price":179.0,"currency_code":"EUR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_3a625792-112b-4d1e-9241-ac0c5c3b90cb.jpg?v=1782402759"},{"product_id":"6550-jj-matched-quad-amplitrex-tested-tubes-new-4-valvole-in-original-box","title":"6550 JJ Matched Quad - AMPLITREX Tested Tubes - NEW - 4 Valves IN ORIGINAL BOX","description":"\u003cp\u003e\u003cstrong\u003e6550 JJ Matched Quad AMPLITREX Tested Tubes (4 Valves) NEW - IN ORIGINAL BOX\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003e \u003cstrong\u003eMADE IN SLOVAK REPUBLIC\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp data-start=\"105\" data-end=\"613\"\u003e The \u003cstrong\u003e6550 JJ\u003c\/strong\u003e represents one of the most appreciated modern power tubes for balance, reliability and dynamic handling.\u003cbr\u003e Designed to deliver consistent performance and full, musical sound, they are individually tested in our lab with \u003cstrong\u003eAmplitrex AT-1000\u003c\/strong\u003e at real operating voltages, to ensure \u003cstrong\u003eaccurate static matching\u003c\/strong\u003e on anode current (Ia) and transconductance (Gm).\u003cbr\u003e Each quartet is selected and electrically verified to offer stability, symmetry and long operating life.\u003c\/p\u003e\n\n\u003cp data-start=\"615\" data-end=\"971\"\u003e \u003cstrong\u003eSelection Process – Technical Check and Sound Consistency\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n\n\u003cli data-start=\"615\" data-end=\"971\"\u003e Testing the \u003cstrong\u003eAmplitrex AT-1000\u003c\/strong\u003e at real-world operating voltages\u003cbr\u003e\u003cstrong\u003e\u003c\/strong\u003e\n\n\u003c\/li\u003e\n\n\u003cli data-start=\"615\" data-end=\"971\"\u003e\n\n \u003cstrong\u003eStatic matching\u003c\/strong\u003e on main parameters (Ia \/ Gm)\u003cbr\u003e\n\n\u003c\/li\u003e\n\n\u003cli data-start=\"615\" data-end=\"971\"\u003e Measurements taken after 10 minutes of preheating\u003cbr\u003e\n\n\u003c\/li\u003e\n\n \u003cli data-start=\"615\" data-end=\"971\"\u003e\n\u003cstrong\u003eMicrophony, emission and isolation\u003c\/strong\u003e control\u003cbr\u003e\n\n\u003c\/li\u003e\n\n\u003cli data-start=\"615\" data-end=\"971\"\u003e Packaged in original box, sealed to ensure authenticity\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cp data-start=\"973\" data-end=\"1619\"\u003e \u003cstrong\u003eSound characteristics\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n\n\u003cli data-start=\"973\" data-end=\"1619\"\u003e\n\n \u003cstrong\u003eBass:\u003c\/strong\u003e solid and tight, with excellent control and articulation. Precise rhythmic foundation, never intrusive.\u003c\/li\u003e\n\n\u003cli data-start=\"973\" data-end=\"1619\"\u003e\n\n \u003cstrong\u003eMids:\u003c\/strong\u003e natural and transparent, with balanced timbre and realism in the voices.\u003c\/li\u003e\n\n\u003cli data-start=\"973\" data-end=\"1619\"\u003e\n\n \u003cstrong\u003eHighs:\u003c\/strong\u003e extended and clean, with harmoniously integrated brilliance and no harshness.\u003c\/li\u003e\n\n\u003cli data-start=\"973\" data-end=\"1619\"\u003e\n\n \u003cstrong\u003eDynamics:\u003c\/strong\u003e prompt and stable, with fluid response and control even at high volumes.\u003c\/li\u003e\n\n\u003cli data-start=\"973\" data-end=\"1619\"\u003e\n\n \u003cstrong\u003eSoundstage:\u003c\/strong\u003e wide and coherent, with good depth and centered soundstage.\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cp data-start=\"973\" data-end=\"1619\"\u003e \u003cstrong\u003e🎧 Ideal for medium and high-end Hi-Fi systems, where balance and musicality are sought.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp data-start=\"973\" data-end=\"1619\"\u003e \u003cstrong\u003e🎸 Excellent for musical amplifiers requiring power, headroom and progressive dynamic response.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp data-start=\"1621\" data-end=\"1688\"\u003e \u003cstrong\u003eTest Specifications\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n\n\u003cli data-start=\"1621\" data-end=\"1688\"\u003e Valves tested on \u003cstrong\u003eAmplitrex AT-1000\u003c\/strong\u003e Tube Tester\u003c\/li\u003e\n\n \u003cli data-start=\"1690\" data-end=\"1747\"\u003e\u003cstrong\u003eMeasurements taken after 10 minutes of preheating\u003c\/strong\u003e\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cp data-start=\"1749\" data-end=\"1775\"\u003e \u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n\n\u003cli data-start=\"1777\" data-end=\"2087\"\u003e\n\n \u003cstrong\u003eMicrophonics:\u003c\/strong\u003e Standard – compliant for use in hi-fi and music amplifiers.\u003c\/li\u003e\n\n\u003cli data-start=\"1777\" data-end=\"2087\"\u003e\n\n \u003cstrong\u003eOutput quality:\u003c\/strong\u003e excellent – ​​strong, stable and smooth output.\u003cbr\u003e\n\n\u003c\/li\u003e\n\n\u003cli data-start=\"1777\" data-end=\"2087\"\u003e\n\n \u003cstrong\u003eShort circuits and GAS:\u003c\/strong\u003e absent.\u003cbr\u003e\n\n\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cp data-start=\"1777\" data-end=\"2087\"\u003e Our 6550 JJ valves are tested and matched to real static parameters, ensuring consistency and reliability over time.\u003c\/p\u003e\n\n\u003cp data-start=\"2089\" data-end=\"2552\"\u003e \u003cstrong\u003eConditions\u003c\/strong\u003e\u003cbr\u003e Supplied in our original box.\u003cbr\u003e Functionality: impeccable.\u003cbr\u003e Factory new valves, tested and in perfect working order.\u003cbr\u003e 24-month legal guarantee (consumers, Legislative Decree 206\/2005). B2B: Articles 1490 et seq. of the Italian Civil Code apply.\u003cbr\u003e Returns for sound preferences\/tube rolling are not accepted. 14-day returns only with intact seal and unused tube.\u003cbr\u003e The warranty covers only original defects in conformity; wear and tear, improper use, and tampering are excluded.\u003c\/p\u003e\n\n\u003cp data-start=\"2905\" data-end=\"3055\"\u003e \u003cstrong\u003eAdditional Information\u003c\/strong\u003e \u003cbr\u003eJJ tubes may exhibit slight variations in glass bulb height, with no impact on performance. \u003c\/p\u003e\n\n\u003cp data-start=\"3058\" data-end=\"3161\" data-is-last-node=\"\" data-is-only-node=\"\"\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cspan style=\"color: rgb(43, 0, 255);\"\u003e\u003cstrong\u003eFAQ - Frequently Asked Questions:\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eRequest:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eAfter installation, do they sound loud right away? Or do they need to be broken in?\u003cbr\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eAnswer:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eThey sound good right out of the box, but they get better with time. After just 50 hours, the bass becomes tight, and around 100 hours, the tonal balance stabilizes. Breaking in is part of the process that makes the sound more natural and engaging.\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e 🔍 Find out what we really think: \u003ca rel=\"noopener\" title=\"Complete Guide to the 6550 JJ Valve\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/guida-completa-alla-valvola-6550-jj\" target=\"_blank\"\u003eread our complete guide to the 6550 JJ.\u003c\/a\u003e\u003c\/p\u003e","brand":"JJ ELECTRONICS","offers":[{"title":"Default Title","offer_id":55705039765852,"sku":"03194","price":229.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_6664b52a-f20a-47a2-bb4d-a5da81c8dd70.jpg?v=1760259409"},{"product_id":"6550-jj-matched-sextet-amplitrex-tested-tubes-new-6-valvole-in-original-box","title":"6550 JJ Matched Sextet - AMPLITREX Tested Tubes - NEW - 6 Valves IN ORIGINAL BOX","description":"\u003cp\u003e \u003cstrong\u003e6550 JJ Matched Sextet - AMPLITREX Tested Tubes (6 Valves) NEW - IN ORIGINAL BOX\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003e \u003cstrong\u003eMADE IN SLOVAK REPUBLIC\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp data-end=\"613\" data-start=\"105\"\u003e The \u003cstrong\u003e6550 JJ\u003c\/strong\u003e represents one of the most appreciated modern power tubes for balance, reliability and dynamic handling.\u003cbr\u003e Designed to deliver consistent performance and full, musical sound, they are individually tested in our lab with \u003cstrong\u003eAmplitrex AT-1000\u003c\/strong\u003e at real operating voltages, to ensure \u003cstrong\u003eaccurate static matching\u003c\/strong\u003e on anode current (Ia) and transconductance (Gm).\u003cbr\u003e Each quartet is selected and electrically verified to offer stability, symmetry and long operating life.\u003c\/p\u003e\n\n\u003cp data-end=\"971\" data-start=\"615\"\u003e \u003cstrong\u003eSelection Process – Technical Check and Sound Consistency\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n\n\u003cli data-end=\"971\" data-start=\"615\"\u003e Testing the \u003cstrong\u003eAmplitrex AT-1000\u003c\/strong\u003e at real-world operating voltages\u003c\/li\u003e\n\n\u003cli data-end=\"971\" data-start=\"615\"\u003e\n\n \u003cstrong\u003eStatic matching\u003c\/strong\u003e on main parameters (Ia \/ Gm)\u003c\/li\u003e\n\n \u003cli data-end=\"971\" data-start=\"615\"\u003eMeasurements taken after 10 minutes of preheating\u003c\/li\u003e\n\n\u003cli data-end=\"971\" data-start=\"615\"\u003e \u003cstrong\u003eMicrophony, emission and isolation\u003c\/strong\u003e control\n\n\u003c\/li\u003e\n\n\u003cli data-end=\"971\" data-start=\"615\"\u003e Packaged in original box, sealed to ensure authenticity\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cp data-end=\"1619\" data-start=\"973\"\u003e \u003cstrong\u003eSound characteristics\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n\n\u003cli data-end=\"1619\" data-start=\"973\"\u003e\n\n \u003cstrong\u003eBass:\u003c\/strong\u003e solid and tight, with excellent control and articulation. Precise rhythmic foundation, never intrusive.\u003c\/li\u003e\n\n\u003cli data-end=\"1619\" data-start=\"973\"\u003e\n\n \u003cstrong\u003eMids:\u003c\/strong\u003e natural and transparent, with balanced timbre and realism in the voices.\u003c\/li\u003e\n\n\u003cli data-end=\"1619\" data-start=\"973\"\u003e\n\n \u003cstrong\u003eHighs:\u003c\/strong\u003e extended and clean, with harmoniously integrated brilliance and no harshness.\u003c\/li\u003e\n\n\u003cli data-end=\"1619\" data-start=\"973\"\u003e\n\n \u003cstrong\u003eDynamics:\u003c\/strong\u003e prompt and stable, with fluid response and control even at high volumes.\u003c\/li\u003e\n\n\u003cli data-end=\"1619\" data-start=\"973\"\u003e\n\n \u003cstrong\u003eSoundstage:\u003c\/strong\u003e wide and coherent, with good depth and centered soundstage.\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cp data-end=\"1619\" data-start=\"973\"\u003e \u003cstrong\u003e🎧 Ideal for medium and high-end Hi-Fi systems, where balance and musicality are sought.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp data-end=\"1619\" data-start=\"973\"\u003e \u003cstrong\u003e🎸 Excellent for musical amplifiers requiring power, headroom and progressive dynamic response.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp data-end=\"1688\" data-start=\"1621\"\u003e \u003cstrong\u003eTest Specifications\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n\n \u003cli data-end=\"1688\" data-start=\"1621\"\u003eValves tested on \u003cstrong\u003eAmplitrex AT-1000\u003c\/strong\u003e Tube Tester\u003c\/li\u003e\n\n\u003cli data-end=\"1747\" data-start=\"1690\"\u003e \u003cstrong\u003eMeasurements taken after 10 minutes of preheating\u003c\/strong\u003e\n\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cp data-end=\"1775\" data-start=\"1749\"\u003e \u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n\n\u003cli data-end=\"2087\" data-start=\"1777\"\u003e\n\n \u003cstrong\u003eMicrophonics:\u003c\/strong\u003e Standard – compliant for use in hi-fi and music amplifiers.\u003c\/li\u003e\n\n\u003cli data-end=\"2087\" data-start=\"1777\"\u003e\n\n \u003cstrong\u003eOutput quality:\u003c\/strong\u003e excellent – ​​strong, stable and smooth output.\u003cbr\u003e\n\n\u003c\/li\u003e\n\n\u003cli data-end=\"2087\" data-start=\"1777\"\u003e\n\n \u003cstrong\u003eShort circuits and GAS:\u003c\/strong\u003e absent.\u003cbr\u003e\n\n\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cp data-end=\"2087\" data-start=\"1777\"\u003e Our 6550 JJ valves are tested and matched to real static parameters, ensuring consistency and reliability over time.\u003c\/p\u003e\n\n\u003cp data-end=\"2552\" data-start=\"2089\"\u003e \u003cstrong\u003eConditions\u003c\/strong\u003e\u003cbr\u003e Supplied in original box.\u003cbr\u003e Functionality: impeccable.\u003cbr\u003e Factory new valves, tested and in perfect working order.\u003cbr\u003e 24-month legal guarantee (consumers, Legislative Decree 206\/2005). B2B: Articles 1490 et seq. of the Italian Civil Code apply.\u003cbr\u003e Returns for sound preferences\/tube rolling are not accepted. 14-day returns only with intact seal and unused tube.\u003cbr\u003e The warranty covers only original defects in conformity; wear and tear, improper use, and tampering are excluded.\u003c\/p\u003e\n\n \u003cp data-end=\"3055\" data-start=\"2905\"\u003e\u003cstrong\u003eAdditional Information\u003c\/strong\u003e\u003cbr\u003e JJ tubes may exhibit slight variations in glass bulb height, with no impact on performance. \u003c\/p\u003e\n\n\u003cp data-is-only-node=\"\" data-is-last-node=\"\" data-end=\"3161\" data-start=\"3058\"\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cspan style=\"color: rgb(43, 0, 255);\"\u003e\u003cstrong\u003eFAQ - Frequently Asked Questions:\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eRequest:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eAfter installation, do they sound loud right away? Or do they need to be broken in?\u003cbr\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eAnswer:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eThey sound good right out of the box, but they get better with time. After just 50 hours, the bass becomes tight, and around 100 hours, the tonal balance stabilizes. Breaking in is part of the process that makes the sound more natural and engaging.\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e 🔍 Find out what we really think: \u003ca href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/guida-completa-alla-valvola-6550-jj\" title=\"Complete Guide to the 6550 JJ Valve\" rel=\"noopener\" target=\"_blank\"\u003eread our complete guide to the 6550 JJ.\u003c\/a\u003e\u003c\/p\u003e","brand":"JJ ELECTRONICS","offers":[{"title":"Default Title","offer_id":55878555009372,"sku":"03247","price":343.5,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_ae406461-e11c-4e46-8181-8e4d3bbc61c6.jpg?v=1762155056"},{"product_id":"jan-6l6wgb-philips-ecg-matched-quad-gray-plates-side-halo-getter-amplitrex-tested-same-date-code-nos-nib","title":"JAN 6L6WGB PHILIPS ECG Matched Quad Gray Plates Side Halo Getter AMPLITREX Tested – Same Date Code – NOS NIB","description":"\u003cp\u003e\u003cstrong\u003eJAN 6L6WGB PHILIPS ECG Matched Quad Gray Plates Side Halo Getter AMPLITREX Tested – Same Date Code – NOS NIB\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cmeta charset=\"utf-8\"\u003eMade in USA – Military Grade – Matched \u0026amp; Balanced Quad\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-start=\"353\" data-end=\"712\"\u003eThis \u003cstrong data-start=\"360\" data-end=\"403\"\u003ematched quartet of 6L6WGB Philips ECGs\u003c\/strong\u003e represents one of the most reliable and musical US military versions ever produced.\u003cbr data-start=\"493\" data-end=\"496\"\u003eMade in the \u003cstrong data-start=\"526\" data-end=\"541\"\u003ePhilips ECG\u003c\/strong\u003e factories to \u003cstrong data-start=\"556\" data-end=\"581\"\u003eJAN (Joint Army-Navy)\u003c\/strong\u003e specifications, these valves combine the construction robustness of the military world with the timbral precision typical of the American school.\u003c\/p\u003e\n\u003cp data-start=\"714\" data-end=\"1183\"\u003eThe \u003cstrong data-start=\"736\" data-end=\"768\"\u003egray plates\u003c\/strong\u003e and \u003cstrong data-start=\"771\" data-end=\"819\"\u003eside halo getter\u003c\/strong\u003e configuration ensures thermal stability, quietness and linear response. \u003cbr data-start=\"880\" data-end=\"883\"\u003eAll four units share \u003cstrong data-start=\"925\" data-end=\"959\"\u003ethe same production code\u003c\/strong\u003e , a sign of perfect batch uniformity and consistent electrical characteristics.\u003cbr data-start=\"1041\" data-end=\"1044\"\u003eTested on \u003cstrong data-start=\"1055\" data-end=\"1076\"\u003eAmplitrex AT-1000\u003c\/strong\u003e , they provided excellent results, with full output and impeccable balance between the tubes in the set.\u003c\/p\u003e\n\u003cp data-end=\"1051\" data-start=\"997\"\u003e\u003cstrong data-end=\"1049\" data-start=\"999\"\u003eTimbre characteristics and sound description\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli data-start=\"1222\" data-end=\"1414\"\u003e\u003cstrong data-start=\"1222\" data-end=\"1232\"\u003eBass:\u003c\/strong\u003e Authoritative and well-controlled, with precise articulation and natural depth. The low range maintains structure and impact even at high volumes, without ever losing definition.\u003c\/li\u003e\n\u003cli data-start=\"1416\" data-end=\"1603\"\u003e\u003cstrong data-start=\"1416\" data-end=\"1425\"\u003eMids:\u003c\/strong\u003e Neutral and transparent, with clean harmonic reproduction and great coherence. Vocals sound natural, fluid, and centered, while acoustic instruments retain body and realism.\u003c\/li\u003e\n\u003cli data-start=\"1605\" data-end=\"1755\"\u003e\u003cstrong data-start=\"1605\" data-end=\"1614\"\u003eHighs:\u003c\/strong\u003e Clear and sweet, with airy extension and a complete lack of harshness. Excellent rendition of fine detail, perfect for long listening sessions.\u003c\/li\u003e\n\u003cli data-start=\"1757\" data-end=\"1963\"\u003e\u003cstrong data-start=\"1757\" data-end=\"1770\"\u003eDynamics:\u003c\/strong\u003e progressive and controlled, with precise transients and an energetic but never excessive response.\u003c\/li\u003e\n\u003cli data-start=\"1757\" data-end=\"1963\"\u003e\u003cstrong data-start=\"1861\" data-end=\"1876\"\u003eSoundstage:\u003c\/strong\u003e wide, stable and three-dimensional, thanks to the excellent matching between the four valves.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-end=\"2026\" data-start=\"1730\"\u003e🎧 \u003cstrong data-end=\"1770\" data-start=\"1733\"\u003eUse in Hi-Fi Stereo Amplifiers\u003c\/strong\u003e\u003cbr data-end=\"1773\" data-start=\"1770\"\u003e\u003cmeta charset=\"utf-8\"\u003e Perfect for \u003cstrong data-end=\"2068\" data-start=\"2033\"\u003estereo push-pull amplifiers or monoblocks\u003c\/strong\u003e , the \u003cstrong data-end=\"2099\" data-start=\"2073\"\u003e6L6WGB Philips ECG JAN\u003c\/strong\u003e offers an ideal combination of \u003cstrong data-end=\"2176\" data-start=\"2135\"\u003erobustness, musicality and silence\u003c\/strong\u003e .\u003cbr data-end=\"2180\" data-start=\"2177\"\u003eParticularly suitable for systems where tonal balance, transparency and constant dynamic performance over time are required.\u003cbr\u003e\u003c\/p\u003e\n\u003cp data-end=\"2288\" data-start=\"2028\"\u003e🎸 \u003cstrong data-end=\"2064\" data-start=\"2031\"\u003eUse in Music Amplifiers\u003c\/strong\u003e\u003cbr data-end=\"2067\" data-start=\"2064\"\u003e\u003cmeta charset=\"utf-8\"\u003e Highly appreciated also in the instrumental field, these tubes offer \u003cstrong data-end=\"2480\" data-start=\"2422\"\u003eample headroom, stable bass and crystal clear mid-highs\u003c\/strong\u003e , with a progressive and musical harmonic distortion.\u003cbr data-end=\"2537\" data-start=\"2534\"\u003eIdeal for \u003cstrong data-end=\"2600\" data-start=\"2562\"\u003eFender, Mesa Boogie and boutique amps\u003c\/strong\u003e , where consistent matching ensures balanced performance and long life.\u003cbr\u003e\u003c\/p\u003e\n\u003cp data-end=\"2706\" data-start=\"2290\"\u003e🎯 \u003cstrong data-end=\"2331\" data-start=\"2293\"\u003eNote for audiophiles and collectors\u003c\/strong\u003e \u003cbr data-end=\"2334\" data-start=\"2331\"\u003e\u003cmeta charset=\"utf-8\"\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli data-end=\"2797\" data-start=\"2731\"\u003e\u003cstrong data-end=\"2795\" data-start=\"2731\"\u003ePhilips ECG Production – Made in USA – Specifications JAN 6L6WGB\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli data-end=\"2849\" data-start=\"2800\"\u003e\u003cstrong data-end=\"2847\" data-start=\"2800\"\u003eGray Plates – robust and linear construction\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli data-end=\"2931\" data-start=\"2852\"\u003e\u003cstrong data-end=\"2929\" data-start=\"2852\"\u003eSide Halo Getter – optimal vacuum maintenance and stable dissipation\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli data-end=\"2985\" data-start=\"2934\"\u003e\u003cstrong data-end=\"2983\" data-start=\"2934\"\u003eSame Date Code – homogeneous and selected batch\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli data-end=\"3073\" data-start=\"2988\"\u003e\u003cstrong data-end=\"3071\" data-start=\"2988\"\u003e💎Amplitrex AT-1000 Test – Uniform output and GM, excellent balance\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli data-end=\"3147\" data-start=\"3076\"\u003e\u003cstrong data-end=\"3147\" data-start=\"3076\"\u003eNOS NIB – New Old Stock, in original Philips ECG boxes\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-end=\"3326\" data-start=\"3149\"\u003eA quartet of excellence, appreciated by technicians, musicians and collectors for their \u003cstrong data-end=\"3268\" data-start=\"3229\"\u003estability, durability and neutral timbre\u003c\/strong\u003e – a true legacy of American military production.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eValve tested on \u003cstrong\u003eAMPLITREX AT-1000\u003c\/strong\u003e Tube Tester:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eTest Conditions:\u003c\/strong\u003e \u003cspan\u003eVa = 350V; Vg2 = 250; Vg = -18V\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eAverage 100%:\u003c\/strong\u003e\u003cspan\u003e\u0026nbsp;\u003c\/span\u003eGm = 5200 ; Ia = 54 mA\u003cbr\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cspan\u003e\u003cstrong\u003eTest result:\u003c\/strong\u003e reading after 10 minutes of warm-up →\u003c\/span\u003e \u003cstrong data-end=\"3815\" data-start=\"3800\"\u003eVERY STRONG\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003eValve #1:\u003c\/strong\u003e Gm = 5350 ; Ia = 58.4 mA\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eValve #4:\u003c\/strong\u003e Gm = 5200 ; Ia = 58.4 mA\u003c\/p\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003eValve #8:\u003c\/strong\u003e Gm = 5100 ; Ia = 57.0 mA\u003c\/p\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003eValve #9:\u003c\/strong\u003e Gm = 5200 ; Ia = 59.4 mA\u003c\/p\u003e\n\u003cdiv\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/div\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e Standard. Tested and approved for use in hi-fi and guitar amplifiers.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eOutput Quality:\u003c\/strong\u003e Excellent – Very strong and stable output, no fluctuations.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eShort circuits and GAS:\u003c\/strong\u003e Absent.\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eConditions:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eCondition:\u003c\/strong\u003e NOS - NIB - New Old Stock, New In Box - Tested and working - Supplied in original box.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eFunctionality:\u003c\/strong\u003e Fully functional.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eCosmetic condition:\u003c\/strong\u003e \u003cspan\u003eExcellent – Excellently preserved lettering, minimal signs of wear. See photos for details.\u003c\/span\u003e\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eManufacturing Code:\u003c\/strong\u003e 84-13 → RMA\/EIA Open Date Code → manufactured 13th week of 1984\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca rel=\"noopener\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"PHILIPS","offers":[{"title":"Default Title","offer_id":55951255667036,"sku":"03262","price":369.0,"currency_code":"EUR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_c254e112-83cc-432b-abf3-e0292fa62ce4.jpg?v=1762971608"},{"product_id":"jan-6l6wgb-philips-ecg-matched-pair-gray-plates-side-halo-getter-amplitrex-tested-same-date-code-nos-nib","title":"JAN 6L6WGB PHILIPS ECG Matched Pair Gray Plates Side Halo Getter AMPLITREX Tested – NOS NIB","description":"\u003cp\u003e\u003cstrong\u003eJAN 6L6WGB PHILIPS ECG Matched Pair Gray Plates Side Halo Getter AMPLITREX Tested – NOS NIB\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cmeta charset=\"utf-8\"\u003eMade in USA – Military Grade – Matched \u0026amp; Balanced Pair\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-end=\"712\" data-start=\"353\"\u003eThis matched \u003cstrong\u003epair\u003c\/strong\u003e \u003cstrong data-end=\"403\" data-start=\"360\"\u003eof 6L6WGB Philips ECGs\u003c\/strong\u003e represent one of the most reliable and musical US military versions ever produced.\u003cbr data-end=\"496\" data-start=\"493\"\u003eMade in the \u003cstrong data-end=\"541\" data-start=\"526\"\u003ePhilips ECG\u003c\/strong\u003e factories to \u003cstrong data-end=\"581\" data-start=\"556\"\u003eJAN (Joint Army-Navy)\u003c\/strong\u003e specifications, these valves combine the construction robustness of the military world with the timbral precision typical of the American school.\u003c\/p\u003e\n\u003cp data-end=\"1183\" data-start=\"714\"\u003eThe \u003cstrong data-end=\"768\" data-start=\"736\"\u003egray plates\u003c\/strong\u003e and \u003cstrong data-end=\"819\" data-start=\"771\"\u003eside halo getter\u003c\/strong\u003e configuration ensures thermal stability, quietness and linear response. \u003cbr data-end=\"883\" data-start=\"880\"\u003eThe specimens share \u003cstrong data-end=\"959\" data-start=\"925\"\u003ethe same internal structure\u003c\/strong\u003e , a sign of perfect uniformity and coherent electrical characteristics.\u003cbr data-end=\"1044\" data-start=\"1041\"\u003eTested on \u003cstrong data-end=\"1076\" data-start=\"1055\"\u003eAmplitrex AT-1000\u003c\/strong\u003e , they provided excellent results, with full output and impeccable balance between the tubes in the set.\u003c\/p\u003e\n\u003cp data-start=\"997\" data-end=\"1051\"\u003e\u003cstrong data-start=\"999\" data-end=\"1049\"\u003eTimbre characteristics and sound description\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli data-end=\"1414\" data-start=\"1222\"\u003e\u003cstrong data-end=\"1232\" data-start=\"1222\"\u003eBass:\u003c\/strong\u003e Authoritative and well-controlled, with precise articulation and natural depth. The low range maintains structure and impact even at high volumes, without ever losing definition.\u003c\/li\u003e\n\u003cli data-end=\"1603\" data-start=\"1416\"\u003e\u003cstrong data-end=\"1425\" data-start=\"1416\"\u003eMids:\u003c\/strong\u003e Neutral and transparent, with clean harmonic reproduction and great coherence. Vocals sound natural, fluid, and centered, while acoustic instruments retain body and realism.\u003c\/li\u003e\n\u003cli data-end=\"1755\" data-start=\"1605\"\u003e\u003cstrong data-end=\"1614\" data-start=\"1605\"\u003eHighs:\u003c\/strong\u003e Clear and sweet, with airy extension and a complete lack of harshness. Excellent rendition of fine detail, perfect for long listening sessions.\u003c\/li\u003e\n\u003cli data-end=\"1963\" data-start=\"1757\"\u003e\u003cstrong data-end=\"1770\" data-start=\"1757\"\u003eDynamics:\u003c\/strong\u003e progressive and controlled, with precise transients and an energetic but never excessive response.\u003c\/li\u003e\n\u003cli data-end=\"1963\" data-start=\"1757\"\u003e\u003cstrong data-end=\"1876\" data-start=\"1861\"\u003eSoundstage:\u003c\/strong\u003e wide, stable and three-dimensional, thanks to the excellent matching between the four valves.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"1730\" data-end=\"2026\"\u003e🎧 \u003cstrong data-start=\"1733\" data-end=\"1770\"\u003eUse in Hi-Fi Stereo Amplifiers\u003c\/strong\u003e\u003cbr data-start=\"1770\" data-end=\"1773\"\u003e\u003cmeta charset=\"utf-8\"\u003e Perfect for \u003cstrong data-start=\"2033\" data-end=\"2068\"\u003estereo push-pull amplifiers or monoblocks\u003c\/strong\u003e , the \u003cstrong data-start=\"2073\" data-end=\"2099\"\u003e6L6WGB Philips ECG JAN\u003c\/strong\u003e offers an ideal combination of \u003cstrong data-start=\"2135\" data-end=\"2176\"\u003erobustness, musicality and silence\u003c\/strong\u003e .\u003cbr data-start=\"2177\" data-end=\"2180\"\u003eParticularly suitable for systems where tonal balance, transparency and constant dynamic performance over time are required.\u003cbr\u003e\u003c\/p\u003e\n\u003cp data-start=\"2028\" data-end=\"2288\"\u003e🎸 \u003cstrong data-start=\"2031\" data-end=\"2064\"\u003eUse in Music Amplifiers\u003c\/strong\u003e\u003cbr data-start=\"2064\" data-end=\"2067\"\u003e\u003cmeta charset=\"utf-8\"\u003e Highly appreciated also in the instrumental field, these tubes offer \u003cstrong data-start=\"2422\" data-end=\"2480\"\u003eample headroom, stable bass and crystal clear mid-highs\u003c\/strong\u003e , with a progressive and musical harmonic distortion.\u003cbr data-start=\"2534\" data-end=\"2537\"\u003eIdeal for \u003cstrong data-start=\"2562\" data-end=\"2600\"\u003eFender, Mesa Boogie and boutique amps\u003c\/strong\u003e , where consistent matching ensures balanced performance and long life.\u003cbr\u003e\u003c\/p\u003e\n\u003cp data-start=\"2290\" data-end=\"2706\"\u003e🎯 \u003cstrong data-start=\"2293\" data-end=\"2331\"\u003eNote for audiophiles and collectors\u003c\/strong\u003e \u003cbr data-start=\"2331\" data-end=\"2334\"\u003e\u003cmeta charset=\"utf-8\"\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli data-start=\"2731\" data-end=\"2797\"\u003e\u003cstrong data-start=\"2731\" data-end=\"2795\"\u003ePhilips ECG Production – Made in USA – Specifications JAN 6L6WGB\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli data-start=\"2800\" data-end=\"2849\"\u003e\u003cstrong data-start=\"2800\" data-end=\"2847\"\u003eGray Plates – robust and linear construction\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli data-start=\"2852\" data-end=\"2931\"\u003e\u003cstrong data-start=\"2852\" data-end=\"2929\"\u003eSide Halo Getter – optimal vacuum maintenance and stable dissipation\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli data-start=\"2988\" data-end=\"3073\"\u003e\u003cstrong data-start=\"2988\" data-end=\"3071\"\u003e💎 Amplitrex AT-1000 Test – Uniform output and GM, excellent balance\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli data-start=\"3076\" data-end=\"3147\"\u003e\u003cstrong data-start=\"3076\" data-end=\"3147\"\u003eNOS NIB – New Old Stock, in original Philips ECG boxes\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"3149\" data-end=\"3326\"\u003eAn excellent pair, appreciated by technicians, musicians and collectors for their \u003cstrong data-start=\"3229\" data-end=\"3268\"\u003estability, durability and neutral timbre\u003c\/strong\u003e – a true legacy of American military production.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eValve tested on \u003cstrong\u003eAMPLITREX AT-1000\u003c\/strong\u003e Tube Tester:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eTest Conditions:\u003c\/strong\u003e \u003cspan\u003eVa = 350V; Vg2 = 250; Vg = -18V\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eAverage 100%:\u003c\/strong\u003e\u003cspan\u003e\u0026nbsp;\u003c\/span\u003eGm = 5.2 ; Ia = 54 mA\u003cbr\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cspan\u003e\u003cstrong\u003eTest result:\u003c\/strong\u003e reading after 10 minutes of warm-up →\u003c\/span\u003e \u003cstrong data-start=\"3800\" data-end=\"3815\"\u003eVERY STRONG\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003eValve #5:\u003c\/strong\u003e Gm = 4.21 ; Ia = 45.6 mA\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eValve #7:\u003c\/strong\u003e Gm = 4.53 ; Ia = 45.2 mA\u003cmeta charset=\"utf-8\"\u003e\u003c\/p\u003e\n\u003cdiv\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/div\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e Standard. Tested and approved for use in hi-fi and guitar amplifiers.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eOutput Quality:\u003c\/strong\u003e Excellent – Very strong and stable output, no fluctuations.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eShort circuits and GAS:\u003c\/strong\u003e Absent.\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eConditions:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eCondition:\u003c\/strong\u003e NOS - NIB - New Old Stock, New In Box - Tested and working - Supplied in original box.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eFunctionality:\u003c\/strong\u003e Fully functional.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eCosmetic condition:\u003c\/strong\u003e \u003cspan\u003eExcellent – Excellently preserved lettering, minimal signs of wear. See photos for details.\u003c\/span\u003e\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eManufacturing Code:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e82-52 → RMA\/EIA Open Date Code → manufactured week 52 of 1982\u003c\/li\u003e\n\u003cli\u003e\u003cmeta charset=\"utf-8\"\u003e 83-52 → RMA\/EIA Open Date Code → manufactured week 52 of 1983\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability and durability\" rel=\"noopener\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"PHILIPS","offers":[{"title":"Default Title","offer_id":55962567541084,"sku":"03463V","price":184.5,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/2_1376be0a-57bb-49ce-9c14-84d758ad688a.jpg?v=1773324197"},{"product_id":"kt77-el34-jj-matched-pair-amplitrex-tested-tubes-new-2-valvole-in-original-box","title":"KT77 EL34 JJ Electronics Matched Pair AMPLITREX Tested NEW Tubes IN ORIGINAL BOX","description":"\u003cp class=\"p1\"\u003e\u003cb\u003eKT77 \/ EL34 JJ Electronics – Matched Pair – AMPLITREX Tested – Original Box\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e\u003cb\u003eMade in Slovakia – Matched Pair – Original Box\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eMatched pair of \u003cspan class=\"s1\"\u003e\u003cb\u003eKT77 JJ Electronics\u003c\/b\u003e\u003c\/span\u003e, \u003cspan class=\"s1\"\u003e\u003cb\u003eMade in Slovakia\u003c\/b\u003e\u003c\/span\u003e, selected for amplifiers compatible with \u003cspan class=\"s1\"\u003e\u003cb\u003eKT77 \/ EL34\u003c\/b\u003e\u003c\/span\u003e where modern reliability, electrical consistency, and a solid, balanced, and authoritative sound reproduction are required.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eThe \u003cspan class=\"s1\"\u003e\u003cb\u003eKT77\u003c\/b\u003e\u003c\/span\u003e is a power tube with an octal base, usable in the vast majority of amplifiers designed for \u003cspan class=\"s1\"\u003e\u003cb\u003eEL34\u003c\/b\u003e\u003c\/span\u003e, when the circuit and biasing allow. Compared to a traditional EL34, it generally offers more authoritative bass, greater headroom, better control, and a more extended presentation, while maintaining good underlying musicality.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eThe \u003cspan class=\"s1\"\u003e\u003cb\u003eJJ Electronics\u003c\/b\u003e\u003c\/span\u003e version represents one of the most appreciated modern interpretations of the KT77, designed to offer stability, current availability, and consistent performance in both hi-fi and musical contexts.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eThe tubes are \u003cspan class=\"s1\"\u003e\u003cb\u003efactory new\u003c\/b\u003e\u003c\/span\u003e, supplied in their respective \u003cspan class=\"s1\"\u003e\u003cb\u003eoriginal JJ boxes\u003c\/b\u003e\u003c\/span\u003e, and have been tested and matched in our laboratory using \u003cspan class=\"s1\"\u003e\u003cb\u003eAmplitrex\u003c\/b\u003e\u003c\/span\u003e, with attention to electrical uniformity, operational stability, and consistent behavior within the amplifier.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eSonically, they offer a modern, balanced, and controlled output, with deep and well-articulated bass, present and natural mids, and open and orderly highs. The dynamic response is prompt and stable, with a feeling of well-managed power and a wide, focused, and credible soundstage.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eSuitable for hi-fi amplifiers compatible with \u003cspan class=\"s1\"\u003e\u003cb\u003eEL34 \/ KT77\u003c\/b\u003e\u003c\/span\u003e, push-pull configurations, and single-ended circuits where provided. In guitar amps, they offer a firmer and more defined sound compared to many traditional EL34s, with greater control over low frequencies and good headroom.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eA new \u003cspan class=\"s1\"\u003e\u003cb\u003eKT77 JJ Electronics\u003c\/b\u003e\u003c\/span\u003e pair, genuinely tested and matched by Vacuum Tubes Treasures, ideal for those wishing to upgrade or maintain EL34-compatible amplifiers at the highest level with a modern, stable, and professional selection.\u003c\/p\u003e\n\u003chr data-end=\"1745\" data-start=\"1742\"\u003e\n\u003ch3 data-end=\"1771\" data-start=\"1747\"\u003eTest Specifications\u003c\/h3\u003e\n\u003cp data-end=\"1884\" data-start=\"1772\"\u003eTubes tested on \u003cstrong data-end=\"1824\" data-start=\"1791\"\u003eAmplitrex AT-1000 Tube Tester\u003c\/strong\u003e\u003cbr data-end=\"1827\" data-start=\"1824\"\u003eMeasurements taken after 10 minutes of pre-heating\u003c\/p\u003e\n\u003cp data-end=\"2082\" data-start=\"1886\"\u003e\u003cstrong data-end=\"1916\" data-start=\"1886\"\u003eAdditional tests performed:\u003c\/strong\u003e\u003cbr data-end=\"1919\" data-start=\"1916\"\u003e• Microphonics: standard – compliant for use in hi-fi and musical instruments\u003cbr data-end=\"1996\" data-start=\"1993\"\u003e• Emission: excellent – strong and stable emission\u003cbr data-end=\"2050\" data-start=\"2047\"\u003e• Short circuits and GAS: none\u003c\/p\u003e\n\u003cp data-end=\"2220\" data-start=\"2084\"\u003eThe pair is matched exclusively on real static parameters, to ensure consistency, reliability, and symmetry between the two channels.\u003c\/p\u003e\n\u003chr data-end=\"2225\" data-start=\"2222\"\u003e\n\u003ch3 data-end=\"2243\" data-start=\"2227\"\u003eConditions\u003c\/h3\u003e\n\u003cp data-end=\"2373\" data-start=\"2244\"\u003e• Supplied in original box\u003cbr data-end=\"2277\" data-start=\"2274\"\u003e• Functionality: impeccable\u003cbr data-end=\"2307\" data-start=\"2304\"\u003e• Factory new tubes, tested and perfectly functional\u003c\/p\u003e\n\u003cp data-end=\"2479\" data-start=\"2375\"\u003e\u003cstrong data-end=\"2388\" data-start=\"2375\"\u003eWarranty:\u003c\/strong\u003e\u003cbr data-end=\"2391\" data-start=\"2388\"\u003e• Consumers: 24 months (Italian Legislative Decree 206\/2005)\u003cbr data-end=\"2434\" data-start=\"2431\"\u003e• B2B: articles 1490 et seq. of the Italian Civil Code apply\u003c\/p\u003e\n\u003chr data-end=\"3076\" data-start=\"3073\"\u003e\n\u003ch3 data-end=\"3107\" data-start=\"3078\"\u003eAdditional Information\u003c\/h3\u003e\n\u003cp data-end=\"3252\" data-start=\"3108\"\u003eJJ tubes may have slight differences in glass envelope height, with no impact on technical or sonic performance.\u003c\/p\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" title=\"Perché le nostre valvole sono diverse – il protocollo VTT che migliora suono, affidabilità e durata\" rel=\"noopener noreferrer\" target=\"_blank\"\u003e\u003cstrong\u003eDiscover why our tubes are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"JJ ELECTRONICS","offers":[{"title":"Default Title","offer_id":56013520339292,"sku":"03276","price":74.5,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/4_5e973561-be48-4897-bd48-67e365a390b0.jpg?v=1782401419"},{"product_id":"6as7ga-6080-ge-nos-nib-black-plate-green-print-matched-pair-amplitrex-tested","title":"6AS7GA \/ 6080 GE NOS NIB Green Label Matched Pair for OTL Amplifiers AMPLITREX Tested USA ’86","description":"\u003ch3 class=\"p1\"\u003e\u003cb\u003e6AS7GA \/ 6080 GE NOS NIB Military Green Label – Matched Pair for OTL Amplifiers – Made in USA 1986\u003c\/b\u003e\u003c\/h3\u003e\n\u003cp class=\"p1\"\u003e\u003cstrong\u003eDirect 6080 Replacement – AMPLITREX Tested – MOLTO FORTE – Real OTL Matching at 55 mA\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch3 class=\"p2\"\u003e\u003cb\u003eDescription\u003c\/b\u003e\u003c\/h3\u003e\n\u003cp class=\"p2\"\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cspan\u003eNot just a simple \"matched\" pair: real selection on Amplitrex for OTL use at 55 mA per section, with attention to stability and consistency between tubes.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eMatched pair of 6AS7GA \/ 6080 GE NOS NIB specifically selected for OTL amplifiers, headphone amplifiers, and circuits compatible with the 6AS7 \/ 6080 family.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eThis is not just a simple NOS pair matched only by brand or date code: the two tubes have been tested and selected in our laboratory for stability, consistency between sections, and real behavior in Auto Bias at 55 mA per section, a particularly significant condition for OTL applications.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eThe tubes have been classified as \u003cspan class=\"s1\"\u003e\u003cb\u003eMOLTO FORTE\u003c\/b\u003e\u003c\/span\u003e (VERY STRONG), with stable emission, well-balanced sections, consistent behavior between the two tubes, no shorts, gas, or instability.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eThese are genuine \u003cspan class=\"s1\"\u003e\u003cb\u003eNOS NIB – New Old Stock, New In Box\u003c\/b\u003e\u003c\/span\u003e tubes, never used, sourced from DLA – Defense Logistics Agency military stock. General Electric production, Made in USA 1986, Owensboro, Kentucky plant, with military green GE silk screen and original packaging.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eThe construction features black plates, a robust internal structure, and a domed chrome getter. The manufacturing code 86-48 identifies the 48th week of 1986.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eSonically, they offer a solid, stable, and musical performance, with full and controlled bass, natural mids, sweet highs, and fluid dynamics. The soundstage is wide, orderly, and well-balanced, favored by the electrical consistency of the pair.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eIdeal for compatible OTL amplifiers, headphone amplifiers, high-current hi-fi circuits, regulators, power buffers, and equipment designed for 6AS7GA \/ 6080.\u003c\/p\u003e\n\u003cp class=\"p3\"\u003eA truly tested and selected military GE NOS pair from Vacuum Tubes Treasures, designed for those seeking authentic, strong, stable American 6AS7GA tubes ready for serious OTL applications.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3 class=\"p1\"\u003e\u003cb\u003eTest Results\u003c\/b\u003e\u003c\/h3\u003e\n\u003cp class=\"p2\"\u003eTubes tested on \u003cspan class=\"s1\"\u003e\u003cb\u003eAMPLITREX AT-1000 Tube Tester\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"p2\"\u003e\u003cb\u003eTest Conditions\u003c\/b\u003e\u003cbr\u003e\u003cstrong\u003eVa =\u003c\/strong\u003e 230V\u003cbr\u003e\u003cstrong\u003eVg =\u003c\/strong\u003e Auto Bias\u003cbr\u003e\u003cstrong\u003eTarget Anode Current:\u003c\/strong\u003e 55 mA per section\u003cbr\u003e\u003cstrong\u003eDissipation:\u003c\/strong\u003e approximately 12.6 W per section, within the maximum limit of 13 W\u003cbr\u003e\u003cstrong\u003eWarm-Up:\u003c\/strong\u003e ≥ 600 seconds for thermal cathode stabilization\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eTube #13\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eSection 1 →\u003c\/strong\u003e Gm = 3540 ; Ia = 55 mA ; Vg = −112 V\u003cbr\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eSection 2 →\u003c\/strong\u003e Gm = 3530 ; Ia = 55 mA ; Vg = −110 V\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eTube #21\u003c\/strong\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eSection 1 →\u003c\/strong\u003e Gm = 3650 ; Ia = 55 mA ; Vg = −111 V\u003cbr\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eSection 2 →\u003c\/strong\u003e Gm = 3640 ; Ia = 55 mA ; Vg = −111 V\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp class=\"p2\"\u003e\u003cb\u003eAdditional Tests\u003c\/b\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli class=\"p2\"\u003eMicrophonics: standard, suitable for hi-fi and musical use\u003cbr\u003e\n\n\u003c\/li\u003e\n\n\u003cli class=\"p2\"\u003eEmission: excellent, stable, without fluctuations\u003cbr\u003e\n\n\u003c\/li\u003e\n\n\u003cli class=\"p2\"\u003eShorts and gas: absent\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp class=\"p2\"\u003e\u003cb\u003eOTL Set\u003c\/b\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli class=\"p2\"\u003eOTL set of 8–12 tubes available upon request with dedicated selection.\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e\u003ca rel=\"noopener\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability, and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eDiscover why our tubes are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"GE","offers":[{"title":"Default Title","offer_id":56143302754652,"sku":"03297M","price":119.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_4b369d2a-ba96-429a-a18b-536d54dcffdb.jpg?v=1762784122"},{"product_id":"6as7ga-6080-ge-nos-nib-black-plate-green-print-matched-pair-amplitrex-tested-copia","title":"6AS7GA \/ 6080 GE NOS NIB Green Label Matched Quad for OTL Amplifiers AMPLITREX Tested USA ’86","description":"\u003ch3 class=\"p1\"\u003e\u003cb\u003e6AS7GA \/ 6080 GE NOS NIB Military Green Label – Matched Quad for OTL Amplifiers – Made in USA 1986\u003c\/b\u003e\u003c\/h3\u003e\n\u003cp class=\"p1\"\u003e\u003cb\u003eDirect 6080 Replacement – AMPLITREX Tested – VERY STRONG – Real OTL Matching at 55 mA\u003c\/b\u003e\u003c\/p\u003e\n\u003ch3 class=\"p2\"\u003e\u003cb\u003eDescription\u003c\/b\u003e\u003c\/h3\u003e\n\u003cp\u003eNot just a simple “matched” quad: real selection on Amplitrex for OTL use at 55 mA per section, with attention to stability and consistency between tubes.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eMatched quad of 6AS7GA \/ 6080 GE NOS NIB specifically selected for OTL amplifiers, headphone amplifiers, balanced stereo configurations, and circuits compatible with the 6AS7 \/ 6080 family that require four consistent, stable, high-current power tubes.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eThis is not a simple NOS quad matched only by brand or date code: the four tubes have been tested and selected in our laboratory for stability, consistency between sections, and real behavior in Auto Bias at 55 mA per section, a particularly significant condition for OTL applications.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eThe tubes have achieved a \u003cspan class=\"s1\"\u003e\u003cb\u003eVERY STRONG\u003c\/b\u003e\u003c\/span\u003e rating, with stable emission, well-balanced internal sections, consistent behavior between all tubes, no shorts, gas, or instability.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eThese are authentic \u003cspan class=\"s1\"\u003e\u003cb\u003eNOS NIB – New Old Stock, New In Box\u003c\/b\u003e\u003c\/span\u003e tubes, never used, sourced from military DLA – Defense Logistics Agency stock. Manufactured by General Electric, Made in USA 1986, Owensboro, Kentucky plant, with GE military green silkscreen and original packaging.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eThe construction features black plates, a robust internal structure, and a domed chrome getter. The manufacturing code 86-48 identifies the 48th week of 1986.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eSonically, they offer a solid, stable, and musical performance, with full and controlled bass, natural mids, sweet highs, and fluid dynamics. The soundstage is wide, organized, and well-balanced, favored by the electrical consistency of the quad.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eIdeal for compatible OTL amplifiers, headphone amplifiers, high-current hi-fi circuits, regulators, power buffers, and equipment designed for 6AS7GA \/ 6080.\u003c\/p\u003e\n\u003cp class=\"p3\"\u003eA truly tested and selected GE NOS military quad from Vacuum Tubes Treasures, designed for those seeking authentic, strong, stable American 6AS7GA tubes ready for serious OTL applications.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3 class=\"p1\"\u003e\u003cb\u003eTest Results\u003c\/b\u003e\u003c\/h3\u003e\n\u003cp class=\"p2\"\u003eTubes tested on \u003cspan class=\"s1\"\u003e\u003cb\u003eAMPLITREX AT-1000 Tube Tester\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"p2\"\u003e\u003cb\u003eTest Conditions\u003c\/b\u003e\u003cbr\u003e\u003cstrong\u003eVa =\u003c\/strong\u003e 230V\u003cbr\u003e\u003cstrong\u003eVg =\u003c\/strong\u003e Auto Bias\u003cbr\u003e\u003cstrong\u003eTarget anode current:\u003c\/strong\u003e 55 mA per section\u003cbr\u003e\u003cstrong\u003eDissipation:\u003c\/strong\u003e approximately 12.6 W per section, within the maximum limit of 13 W\u003cbr\u003e\u003cstrong\u003eWarm-Up:\u003c\/strong\u003e ≥ 600 seconds for cathode thermal stabilization\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eTube #16\u003c\/strong\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003eSection 1 → Gm = 3250 ; Ia = 55 mA ; Vg = -115 V\u003c\/li\u003e\n\n\u003cli\u003eSection 2 → Gm = 3470 ; Ia = 55 mA ; Vg = -111 V\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eTube #17\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003eSection 1 → Gm = 3450 ; Ia = 55 mA ; Vg = -110 V\u003c\/li\u003e\n\n\u003cli\u003eSection 2 → Gm = 3320 ; Ia = 55 mA ; Vg = -113 V\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eTube #20\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003eSection 1 → Gm = 3160 ; Ia = 55 mA ; Vg = -117 V\u003c\/li\u003e\n\n\u003cli\u003eSection 2 → Gm = 3640 ; Ia = 55 mA ; Vg = -110 V\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eTube #3\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003eSection 1 → Gm = 3180 ; Ia = 55 mA ; Vg = -112 V\u003c\/li\u003e\n\n\u003cli\u003eSection 2 → Gm = 3500 ; Ia = 55 mA ; Vg = -113 V\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eAdditional Tests\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003eMicrophonics: standard, suitable for hi-fi and musical use\u003c\/li\u003e\n\n\u003cli\u003eEmission: excellent, stable, without fluctuations\u003cbr\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003eShorts and gas: absent\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eOTL Set (8–12 tubes) → on request \/ dedicated selection\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003ca rel=\"noopener\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eDiscover why our tubes are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"GE","offers":[{"title":"Default Title","offer_id":56145394237788,"sku":"03298Q","price":239.8,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/3_bca0378d-2981-4ce5-9c14-ca06e505b874.jpg?v=1764867493"},{"product_id":"7189-sherwood-by-philips-heerlen-1963-gray-plates-δx4-matched-quad-tested-100","title":"7189 SHERWOOD by Philips – Heerlen 1963 – Gray Plates – rx4 – Matched Quad – Tested 100%","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cstrong\u003e7189 SHERWOOD by Philips – Heerlen 1963 – Gray Plates – rx4 – Matched Quad – Tested 100% - Made in HOLLAND\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-start=\"0\" data-end=\"769\"\u003eThis \u003cstrong data-start=\"37\" data-end=\"86\"\u003ematched quartet of 7189 Sherwood by Philips\u003c\/strong\u003e , produced \u003cstrong data-start=\"99\" data-end=\"124\"\u003ein Heerlen (Holland) in 1963\u003c\/strong\u003e , belongs to the prestigious line made by Philips for Sherwood, one of the most reliable and musical combinations of the time.\u003cbr data-start=\"256\" data-end=\"259\"\u003eThis is the \u003cstrong data-start=\"284\" data-end=\"299\"\u003egray plates\u003c\/strong\u003e variant with factory coding \u003cstrong data-start=\"322\" data-end=\"329\"\u003erX4\u003c\/strong\u003e , one of the most recognizable signatures of Heerlen productions from the early 60s, known for its stability, build quality and high-level sound reproduction. \u003cbr data-start=\"480\" data-end=\"483\"\u003eThe set was selected in our laboratory as a \u003cstrong data-start=\"538\" data-end=\"554\"\u003eMatched Quad\u003c\/strong\u003e , with coherent electrical behavior and uniform timbre across all specimens. Bench testing confirmed \u003cstrong data-start=\"689\" data-end=\"697\"\u003e100%\u003c\/strong\u003e performance, with solid output, excellent linearity, and perfect operational stability.\u003c\/p\u003e\n\u003cp data-start=\"771\" data-end=\"1088\"\u003e\u003cstrong data-start=\"773\" data-end=\"799\"\u003eSound Characteristics\u003c\/strong\u003e\u003cbr data-start=\"799\" data-end=\"802\"\u003eThe 1963 Philips Heerlen 7189s are renowned for their combination of power, musicality and refinement.\u003cbr data-start=\"911\" data-end=\"914\"\u003eThe presentation is bright, defined and rich in micro-detail, with a tonal balance that places them among the best European interpretations of the EL84\/7189 family.\u003c\/p\u003e\n\u003cp data-start=\"1090\" data-end=\"1235\"\u003e\u003cstrong data-start=\"1090\" data-end=\"1099\"\u003eBass\u003c\/strong\u003e\u003cbr data-start=\"1099\" data-end=\"1102\"\u003eTight, fast, and compact. The low end is precise and controlled, without any bloat, with a powerful yet balanced response.\u003c\/p\u003e\n\u003cp data-start=\"1237\" data-end=\"1436\"\u003e\u003cstrong data-start=\"1237\" data-end=\"1245\"\u003eMedium\u003c\/strong\u003e \u003cbr data-start=\"1245\" data-end=\"1248\"\u003eThe strong point of Heerlen's production. \u003cstrong data-start=\"1297\" data-end=\"1341\"\u003eAiry, transparent mids, rich in harmonics\u003c\/strong\u003e , with realistic and natural voices. Excellent performance on acoustic instruments, jazz, and vocal music.\u003c\/p\u003e\n\u003cp data-start=\"1438\" data-end=\"1585\"\u003e\u003cstrong data-start=\"1438\" data-end=\"1446\"\u003eHigh\u003c\/strong\u003e\u003cbr data-start=\"1446\" data-end=\"1449\"\u003eBright, silky, and well-extended. The highs are defined and fluid, without harshness, with a finesse typical of vintage Philips EL84s.\u003c\/p\u003e\n\u003cp data-start=\"1587\" data-end=\"1790\"\u003e\u003cstrong data-start=\"1587\" data-end=\"1599\"\u003eDynamics\u003c\/strong\u003e\u003cbr data-start=\"1599\" data-end=\"1602\"\u003eLively, responsive, with excellent control at high volume.\u003cbr data-start=\"1660\" data-end=\"1663\"\u003eThe response is clean, stable, with great ability to follow transients and an energetic output without unwanted compression.\u003c\/p\u003e\n\u003cp data-start=\"1792\" data-end=\"1962\"\u003e\u003cstrong data-start=\"1792\" data-end=\"1806\"\u003eSoundstage\u003c\/strong\u003e\u003cbr data-start=\"1806\" data-end=\"1809\"\u003eWide, three-dimensional soundstage, with clear separation of musical lines. Excellent focus and depth, with a solid, well-layered image.\u003c\/p\u003e\n\u003cp data-start=\"1964\" data-end=\"2036\"\u003e🎧 \u003cstrong data-start=\"1967\" data-end=\"2004\"\u003eUse in Hi-Fi Stereo Amplifiers\u003c\/strong\u003e\u003cbr data-start=\"2004\" data-end=\"2007\"\u003ePerfect for amplifiers:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli data-start=\"2039\" data-end=\"2077\"\u003eSherwood, Fisher and Scott of the time,\u003c\/li\u003e\n\u003cli data-start=\"2080\" data-end=\"2149\"\u003eEuropean amplifiers requiring 7189 for higher voltages,\u003c\/li\u003e\n\u003cli data-start=\"2152\" data-end=\"2213\"\u003esystems where clarity, naturalness and dynamics are desired.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"2215\" data-end=\"2241\"\u003eThe quartet guarantees:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli data-start=\"2244\" data-end=\"2264\"\u003euniform timbre,\u003c\/li\u003e\n\u003cli data-start=\"2267\" data-end=\"2296\"\u003eremarkable thermal stability,\u003c\/li\u003e\n\u003cli data-start=\"2299\" data-end=\"2337\"\u003ehigher headroom than common EL84s.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"2339\" data-end=\"2411\"\u003eIdeal for jazz, vocal, classical, fusion and high definition listening.\u003c\/p\u003e\n\u003cp data-start=\"2413\" data-end=\"2539\"\u003e🎸 \u003cstrong data-start=\"2416\" data-end=\"2449\"\u003eUse in Music Amplifiers\u003c\/strong\u003e\u003cbr data-start=\"2449\" data-end=\"2452\"\u003eIn music, the 7189 is highly regarded in vintage high-voltage amps such as:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli data-start=\"2542\" data-end=\"2561\"\u003eGibson GA-series,\u003c\/li\u003e\n\u003cli data-start=\"2564\" data-end=\"2613\"\u003eAmerican amplifiers with hot cathode bias,\u003c\/li\u003e\n\u003cli data-start=\"2616\" data-end=\"2691\"\u003eboutique projects requiring more robustness than standard EL84s.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"2693\" data-end=\"2703\"\u003eThey offer:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli data-start=\"2706\" data-end=\"2743\"\u003eprogressive and musical distortion,\u003c\/li\u003e\n\u003cli data-start=\"2746\" data-end=\"2781\"\u003egreat control over harmonics,\u003c\/li\u003e\n\u003cli data-start=\"2784\" data-end=\"2814\"\u003ewider and cleaner headroom.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"2816\" data-end=\"2906\"\u003e🎯 \u003cstrong data-start=\"2819\" data-end=\"2851\"\u003eNote for audiophiles and technicians\u003c\/strong\u003e\u003cbr data-start=\"2851\" data-end=\"2854\"\u003eThis \u003cstrong data-start=\"2861\" data-end=\"2894\"\u003eMatched Quad Heerlen 1963 rX4\u003c\/strong\u003e features:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli data-start=\"2909\" data-end=\"2957\"\u003ecareful selection for uniform behavior,\u003c\/li\u003e\n\u003cli data-start=\"2960\" data-end=\"2979\"\u003e\u003cstrong data-start=\"2968\" data-end=\"2976\"\u003e100%\u003c\/strong\u003e test,\u003c\/li\u003e\n\u003cli data-start=\"2982\" data-end=\"3019\"\u003eoperational stability and silence,\u003c\/li\u003e\n\u003cli data-start=\"3022\" data-end=\"3068\"\u003ehigh-end historic Philips building,\u003c\/li\u003e\n\u003cli data-start=\"3071\" data-end=\"3170\"\u003ePerfect compatibility with vintage devices that require real 7189s, not modern equivalents.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"3172\" data-end=\"3361\"\u003eAn ideal set for restoration, upgrade or use in high precision hi-fi amplifiers.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eValve tested on \u003cstrong\u003eAMPLITREX AT-1000\u003c\/strong\u003e Tube Tester:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eTest Conditions:\u003c\/strong\u003e \u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003eVa = 250V, Vg2 = 250V, Vg = -7.3V\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eAverage 100%:\u003c\/strong\u003e \u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003eGm = 11.3 ; Ia = 48 mA\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eTest Result:\u003c\/strong\u003e VERY STRONG\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eValve 1:\u003c\/strong\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cspan\u003eGm = 11.2 ; Ia = 48.4 mA\u003c\/span\u003e\u003cstrong\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003eValve 2:\u003c\/strong\u003e\u003cmeta charset=\"utf-8\"\u003e Gm = 11.0 ; Ia = 48.0 mA\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003eValve 3:\u003c\/strong\u003e\u003cmeta charset=\"utf-8\"\u003e Gm = 11.0 ; Ia = 48.0 mA\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003eValve 4:\u003c\/strong\u003e\u003cmeta charset=\"utf-8\"\u003e Gm = 11.4 ; Ia = 49.4 mA\u003c\/span\u003e\u003c\/p\u003e\n\u003cdiv\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/div\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e Low. Tested and approved for use in hi-fi and guitar amplifiers.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eOutput Quality:\u003c\/strong\u003e Excellent – Very strong and stable output, no fluctuations.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eShort circuits and GAS:\u003c\/strong\u003e Absent.\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eConditions:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eCondition:\u003c\/strong\u003e Vintage tubes - Tested and in perfect working order. Shipped in our custom box for optimal protection.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eFunctionality:\u003c\/strong\u003e Fully functional.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eAesthetic condition:\u003c\/strong\u003e Very good – Clearly legible writing with minor signs of wear, no obvious defects. See photos for details.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eManufacturing Code:\u003c\/strong\u003e\u003cstrong\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003erx4 Δ3A3 →\u003cmeta charset=\"utf-8\"\u003e rxx indicates a 7189 with the sequential progression of x, where the increment of x indicates the production changes - \u003cmeta charset=\"utf-8\"\u003eΔ3A3 Δ → Heerlen (Netherlands), 3 (out of four digits) → 1963 - A → January - 3 → 3rd week of the month\u003c\/li\u003e\n\u003cli\u003e\u003cmeta charset=\"utf-8\"\u003e rx4 Δ3A2 →\u003cmeta charset=\"utf-8\"\u003e rxx indicates a 7189 with the sequential progression of x, where the increment of x indicates the production changes -\u003cmeta charset=\"utf-8\"\u003e Δ3A3 Δ → Heerlen (Netherlands), 3 (out of four digits) → 1963 - A → January - 2 → 2nd week of the month\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca rel=\"noopener\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"PHILIPS","offers":[{"title":"Default Title","offer_id":56200573747548,"sku":"03309","price":289.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_66567479-58c7-43ce-8537-6e28121c233e.jpg?v=1765391469"},{"product_id":"7189-sherwood-by-philips-heerlen-1963-gray-plates-rx4-matched-pair-tested-100","title":"7189 SHERWOOD by Philips – Heerlen 1963 – Gray Plates – rx4 – Matched Pair – Tested 100%","description":"\u003cp\u003e\u003cstrong\u003e7189 SHERWOOD by Philips – Heerlen 1963 – Gray Plates – rx4 – Matched Pair – Tested 100% - Made in HOLLAND\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-start=\"0\" data-end=\"769\"\u003eThis matched \u003cstrong\u003epair\u003c\/strong\u003e \u003cstrong data-start=\"37\" data-end=\"86\"\u003eof 7189 Sherwood by Philips\u003c\/strong\u003e , produced \u003cstrong data-start=\"99\" data-end=\"124\"\u003ein Heerlen (Holland) in 1963\u003c\/strong\u003e , belongs to the prestigious line made by Philips for Sherwood, one of the most reliable and musical combinations of the time.\u003cbr data-start=\"256\" data-end=\"259\"\u003eThis is the \u003cstrong data-start=\"284\" data-end=\"299\"\u003egray plates\u003c\/strong\u003e variant with factory coding \u003cstrong data-start=\"322\" data-end=\"329\"\u003erX4\u003c\/strong\u003e , one of the most recognizable signatures of Heerlen productions from the early 60s, known for its stability, build quality and high-level sound reproduction. \u003cbr data-start=\"480\" data-end=\"483\"\u003eThe set was selected in our laboratory as a \u003cstrong data-start=\"538\" data-end=\"554\"\u003eMatched Pair\u003c\/strong\u003e , with coherent electrical behavior and uniform timbre across all specimens. Bench testing confirmed \u003cstrong data-start=\"689\" data-end=\"697\"\u003e100%\u003c\/strong\u003e performance, with solid output, excellent linearity, and perfect operational stability.\u003c\/p\u003e\n\u003cp data-start=\"771\" data-end=\"1088\"\u003e\u003cstrong data-start=\"773\" data-end=\"799\"\u003eSound Characteristics\u003c\/strong\u003e\u003cbr data-start=\"799\" data-end=\"802\"\u003eThe 1963 Philips Heerlen 7189s are renowned for their combination of power, musicality and refinement.\u003cbr data-start=\"911\" data-end=\"914\"\u003eThe presentation is bright, defined and rich in micro-detail, with a tonal balance that places them among the best European interpretations of the EL84\/7189 family.\u003c\/p\u003e\n\u003cp data-start=\"1090\" data-end=\"1235\"\u003e\u003cstrong data-start=\"1090\" data-end=\"1099\"\u003eBass\u003c\/strong\u003e\u003cbr data-start=\"1099\" data-end=\"1102\"\u003eTight, fast, and compact. The low end is precise and controlled, without any bloat, with a powerful yet balanced response.\u003c\/p\u003e\n\u003cp data-start=\"1237\" data-end=\"1436\"\u003e\u003cstrong data-start=\"1237\" data-end=\"1245\"\u003eMedium\u003c\/strong\u003e \u003cbr data-start=\"1245\" data-end=\"1248\"\u003eThe strong point of Heerlen's production. \u003cstrong data-start=\"1297\" data-end=\"1341\"\u003eAiry, transparent mids, rich in harmonics\u003c\/strong\u003e , with realistic and natural voices. Excellent performance on acoustic instruments, jazz, and vocal music.\u003c\/p\u003e\n\u003cp data-start=\"1438\" data-end=\"1585\"\u003e\u003cstrong data-start=\"1438\" data-end=\"1446\"\u003eHigh\u003c\/strong\u003e\u003cbr data-start=\"1446\" data-end=\"1449\"\u003eBright, silky, and well-extended. The highs are defined and fluid, without harshness, with a finesse typical of vintage Philips EL84s.\u003c\/p\u003e\n\u003cp data-start=\"1587\" data-end=\"1790\"\u003e\u003cstrong data-start=\"1587\" data-end=\"1599\"\u003eDynamics\u003c\/strong\u003e\u003cbr data-start=\"1599\" data-end=\"1602\"\u003eLively, responsive, with excellent control at high volume.\u003cbr data-start=\"1660\" data-end=\"1663\"\u003eThe response is clean, stable, with great ability to follow transients and an energetic output without unwanted compression.\u003c\/p\u003e\n\u003cp data-start=\"1792\" data-end=\"1962\"\u003e\u003cstrong data-start=\"1792\" data-end=\"1806\"\u003eSoundstage\u003c\/strong\u003e\u003cbr data-start=\"1806\" data-end=\"1809\"\u003eWide, three-dimensional soundstage, with clear separation of musical lines. Excellent focus and depth, with a solid, well-layered image.\u003c\/p\u003e\n\u003cp data-start=\"1964\" data-end=\"2036\"\u003e🎧 \u003cstrong data-start=\"1967\" data-end=\"2004\"\u003eUse in Hi-Fi Stereo Amplifiers\u003c\/strong\u003e\u003cbr data-start=\"2004\" data-end=\"2007\"\u003ePerfect for amplifiers:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli data-start=\"2039\" data-end=\"2077\"\u003eSherwood, Fisher and Scott of the time,\u003c\/li\u003e\n\u003cli data-start=\"2080\" data-end=\"2149\"\u003eEuropean amplifiers requiring 7189 for higher voltages,\u003c\/li\u003e\n\u003cli data-start=\"2152\" data-end=\"2213\"\u003esystems where clarity, naturalness and dynamics are desired.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"2215\" data-end=\"2241\"\u003eThe couple guarantees:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli data-start=\"2244\" data-end=\"2264\"\u003euniform timbre,\u003c\/li\u003e\n\u003cli data-start=\"2267\" data-end=\"2296\"\u003eremarkable thermal stability,\u003c\/li\u003e\n\u003cli data-start=\"2299\" data-end=\"2337\"\u003ehigher headroom than common EL84s.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"2339\" data-end=\"2411\"\u003eIdeal for jazz, vocal, classical, fusion and high definition listening.\u003c\/p\u003e\n\u003cp data-start=\"2413\" data-end=\"2539\"\u003e🎸 \u003cstrong data-start=\"2416\" data-end=\"2449\"\u003eUse in Music Amplifiers\u003c\/strong\u003e\u003cbr data-start=\"2449\" data-end=\"2452\"\u003eIn music, the 7189 is highly regarded in vintage high-voltage amps such as:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli data-start=\"2542\" data-end=\"2561\"\u003eGibson GA-series,\u003c\/li\u003e\n\u003cli data-start=\"2564\" data-end=\"2613\"\u003eAmerican amplifiers with hot cathode bias,\u003c\/li\u003e\n\u003cli data-start=\"2616\" data-end=\"2691\"\u003eboutique projects requiring more robustness than standard EL84s.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"2693\" data-end=\"2703\"\u003eThey offer:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli data-start=\"2706\" data-end=\"2743\"\u003eprogressive and musical distortion,\u003c\/li\u003e\n\u003cli data-start=\"2746\" data-end=\"2781\"\u003egreat control over harmonics,\u003c\/li\u003e\n\u003cli data-start=\"2784\" data-end=\"2814\"\u003ewider and cleaner headroom.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"2816\" data-end=\"2906\"\u003e🎯 \u003cstrong data-start=\"2819\" data-end=\"2851\"\u003eNote for audiophiles and technicians\u003c\/strong\u003e\u003cbr data-start=\"2851\" data-end=\"2854\"\u003eThis \u003cstrong data-start=\"2861\" data-end=\"2894\"\u003eMatched Pair Heerlen 1963 rX4\u003c\/strong\u003e features:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli data-start=\"2909\" data-end=\"2957\"\u003ecareful selection for uniform behavior,\u003c\/li\u003e\n\u003cli data-start=\"2960\" data-end=\"2979\"\u003e\u003cstrong data-start=\"2968\" data-end=\"2976\"\u003e100%\u003c\/strong\u003e test,\u003c\/li\u003e\n\u003cli data-start=\"2982\" data-end=\"3019\"\u003eoperational stability and silence,\u003c\/li\u003e\n\u003cli data-start=\"3022\" data-end=\"3068\"\u003ehigh-end historic Philips building,\u003c\/li\u003e\n\u003cli data-start=\"3071\" data-end=\"3170\"\u003ePerfect compatibility with vintage devices that require real 7189s, not modern equivalents.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"3172\" data-end=\"3361\"\u003eAn ideal set for restoration, upgrade or use in high precision hi-fi amplifiers.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eValve tested on \u003cstrong\u003eAMPLITREX AT-1000\u003c\/strong\u003e Tube Tester:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eTest Conditions:\u003c\/strong\u003e \u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003eVa = 250V, Vg2 = 250V, Vg = -7.3V\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eAverage 100%:\u003c\/strong\u003e \u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003eGm = 11.3 ; Ia = 48 mA\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eTest Result:\u003c\/strong\u003e VERY STRONG\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eValve 1:\u003c\/strong\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cspan\u003eGm = 10.85 ; Ia = 45.4 mA\u003c\/span\u003e\u003cstrong\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003eValve 2:\u003c\/strong\u003e\u003cmeta charset=\"utf-8\"\u003e Gm = 10.80 ; Ia = 45.0 mA\u003c\/span\u003e\u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cdiv\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/div\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e Low. Tested and approved for use in hi-fi and guitar amplifiers.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eOutput Quality:\u003c\/strong\u003e Excellent – Very strong and stable output, no fluctuations.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eShort circuits and GAS:\u003c\/strong\u003e Absent.\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eConditions:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eCondition:\u003c\/strong\u003e Vintage tubes - Tested and in perfect working order. Shipped in our custom box for optimal protection.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eFunctionality:\u003c\/strong\u003e Fully functional.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eAesthetic condition:\u003c\/strong\u003e Very good – Clearly legible writing with minor signs of wear, no obvious defects. See photos for details.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eManufacturing Code:\u003c\/strong\u003e\u003cstrong\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003erx4 Δ3A3 →\u003cmeta charset=\"utf-8\"\u003e rxx indicates a 7189 with the sequential progression of x, where the increment of x indicates the production changes -\u003cmeta charset=\"utf-8\"\u003e Δ3A3 Δ → Heerlen (Netherlands), 3 (out of four digits) → 1963 - A → January - 3 → 3rd week of the month\u003cmeta charset=\"utf-8\"\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca rel=\"noopener\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"PHILIPS","offers":[{"title":"Default Title","offer_id":56207309209948,"sku":"03310","price":144.5,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/2_f14d5939-ff93-42be-83b1-0f21e64d5892.jpg?v=1765451799"}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/collections\/power-tubes-439235.jpg?v=1657112578","url":"https:\/\/vacuumtubestreasures.com\/en-hr\/collections\/power-tubes-en.oembed?page=5","provider":"Vacuum Tubes Treasures","version":"1.0","type":"link"}