{"product_id":"6550-magnavox-by-tung-sol-type-2-4th-generation-amplitrex-matched-quad-strong-made-in-usa-1","title":"6550 MAGNAVOX by TUNG-SOL Type 2 – 4th Generation - AMPLITREX Matched Quad - Made in USA","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003e6550 MAGNAVOX by TUNG-SOL Type 2 - 4th Generation Gray Plates Triple Halo Getter Three Holes Matched Quad 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=\"909\" data-start=\"386\"\u003eThis \u003cstrong data-end=\"437\" data-start=\"393\"\u003ematched quartet of 6550 MAGNAVOX by Tung-Sol\u003c\/strong\u003e , Made in USA, belongs to the \u003cstrong data-end=\"495\" data-start=\"468\"\u003eType 2 – 4th generation\u003c\/strong\u003e , one of the most mature and musically balanced versions of the historic American 6550.\u003cbr data-end=\"586\" data-start=\"583\"\u003eThe construction with \u003cstrong data-end=\"620\" data-start=\"605\"\u003egray plates\u003c\/strong\u003e , \u003cstrong data-end=\"644\" data-start=\"622\"\u003etriple halo getter\u003c\/strong\u003e and \u003cstrong data-end=\"675\" data-start=\"647\"\u003ethree ventilation holes\u003c\/strong\u003e reflects a production phase oriented towards maximum electrical stability, controlled thermal dissipation and long operational reliability, maintaining intact the authoritative sound character typical of the best vintage 6550s.\u003c\/p\u003e\n\u003cp data-end=\"1259\" data-start=\"911\"\u003eThe set was \u003cstrong data-end=\"959\" data-start=\"926\"\u003eselected as Matched Quad\u003c\/strong\u003e and tested with professional equipment, it features the same manufacturing code on the entire quartet with homogeneous behavior and consistent response on all tubes.\u003cbr data-end=\"1102\" data-start=\"1099\"\u003eThis is a quartet designed for medium-high and high-end amplifiers, where balance, control and tonal solidity are fundamental requirements.\u003c\/p\u003e\n\u003chr data-end=\"1264\" data-start=\"1261\"\u003e\n\u003ch3 data-end=\"1286\" data-start=\"1266\"\u003eSound Character\u003c\/h3\u003e\n\u003cp data-end=\"1487\" data-start=\"1288\"\u003e\u003cstrong data-end=\"1297\" data-start=\"1288\"\u003eBass\u003c\/strong\u003e\u003cbr data-end=\"1300\" data-start=\"1297\"\u003eDeep, compact, and perfectly controlled. The low end is authoritative but never intrusive, with excellent articulation and the ability to sustain complex loads without losing definition.\u003c\/p\u003e\n\u003cp data-end=\"1677\" data-start=\"1489\"\u003e\u003cstrong data-end=\"1497\" data-start=\"1489\"\u003eMedium\u003c\/strong\u003e\u003cbr data-end=\"1500\" data-start=\"1497\"\u003eBalanced, full, and natural. The vocals are solid and well-focused, with a rich yet composed harmonic texture. They perform excellently on jazz, classic rock, and orchestral repertoire.\u003c\/p\u003e\n\u003cp data-end=\"1866\" data-start=\"1679\"\u003e\u003cstrong data-end=\"1687\" data-start=\"1679\"\u003eHigh\u003c\/strong\u003e \u003cbr data-end=\"1690\" data-start=\"1687\"\u003eClean, extended, and uncluttered. The highs are present but never aggressive, with a balance that favors prolonged listening and delivers air and detail without fatiguing.\u003c\/p\u003e\n\u003cp data-end=\"2017\" data-start=\"1868\"\u003e\u003cstrong data-end=\"1880\" data-start=\"1868\"\u003eDynamics\u003c\/strong\u003e\u003cbr data-end=\"1883\" data-start=\"1880\"\u003eConvincing and stable. Transient response is prompt yet controlled, with a sense of always-available power reserves.\u003c\/p\u003e\n\u003cp data-end=\"2175\" data-start=\"2019\"\u003e\u003cstrong data-end=\"2033\" data-start=\"2019\"\u003eSoundstage\u003c\/strong\u003e\u003cbr data-end=\"2036\" data-start=\"2033\"\u003eWide and well-structured, with a solid and credible soundstage. Excellent separation of levels and stable imaging even at high volumes.\u003c\/p\u003e\n\u003chr data-end=\"2180\" data-start=\"2177\"\u003e\n\u003ch3 data-end=\"2215\" data-start=\"2182\"\u003e🎧 Use in Hi-Fi Amplifiers\u003c\/h3\u003e\n\u003cp data-end=\"2227\" data-start=\"2216\"\u003eIdeal for:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli data-end=\"2262\" data-start=\"2230\"\u003e6550 push-pull amplifiers\u003c\/li\u003e\n\u003cli data-end=\"2305\" data-start=\"2265\"\u003efinal and integrated courses in American schools\u003c\/li\u003e\n\u003cli data-end=\"2383\" data-start=\"2308\"\u003esystems that require \u003cstrong data-end=\"2371\" data-start=\"2331\"\u003ebalance, control and reliability\u003c\/strong\u003e over time\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-end=\"2525\" data-start=\"2385\"\u003eAn excellent choice for those who want the classic 6550 sound in a more modern and balanced version than the very first generations.\u003c\/p\u003e\n\u003chr data-end=\"2530\" data-start=\"2527\"\u003e\n\u003ch3 data-end=\"2567\" data-start=\"2532\"\u003e🎸 Use in Music Applications\u003c\/h3\u003e\n\u003cp data-end=\"2583\" data-start=\"2568\"\u003eAppreciated for:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli data-end=\"2638\" data-start=\"2586\"\u003ehigh-powered bass and guitar amplifiers\u003c\/li\u003e\n\u003cli data-end=\"2732\" data-start=\"2641\"\u003eprofessional applications where stability, headroom and predictable response are required\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-end=\"2825\" data-start=\"2734\"\u003eThey offer a solid, defined and resistant sound even under demanding conditions of use.\u003c\/p\u003e\n\u003chr data-end=\"2830\" data-start=\"2827\"\u003e\n\u003ch3 data-end=\"2869\" data-start=\"2832\"\u003e🎯 Note for audiophiles and technicians\u003c\/h3\u003e\n\u003cp data-end=\"2953\" data-start=\"2870\"\u003eThis \u003cstrong data-end=\"2940\" data-start=\"2877\"\u003eMatched Quad of 6550 MAGNAVOX by Tung-Sol Type 2 – 4th Generation\u003c\/strong\u003e represents:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli data-end=\"3033\" data-start=\"2956\"\u003eone of the most reliable and musically balanced versions of the 6550 USA\u003c\/li\u003e\n\u003cli data-end=\"3094\" data-start=\"3036\"\u003eRobust construction with triple halo getters and gray plates\u003c\/li\u003e\n\u003cli data-end=\"3125\" data-start=\"3097\"\u003eaccurate matched selection\u003cbr\u003e\u003c\/li\u003e\n\u003cli data-end=\"3125\" data-start=\"3097\"\u003esame manufacturing code\u003c\/li\u003e\n\u003cli data-end=\"3231\" data-start=\"3149\"\u003eexcellent compromise between \u003cstrong data-end=\"3231\" data-start=\"3176\"\u003esound performance, durability and collectible value\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-is-only-node=\"\" data-is-last-node=\"\" data-end=\"3388\" data-start=\"3233\"\u003eAn ideal quartet for those looking for \u003cstrong data-end=\"3360\" data-start=\"3267\"\u003ereal performance, tonal coherence and the authentic character of the great American 6550s\u003c\/strong\u003e , without unnecessary compromises.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eTested on \u003cstrong\u003eAMPLITREX AT-1000\u003c\/strong\u003e Tube tester: \u003cbr\u003e\u003cstrong\u003eTest Conditions:\u003c\/strong\u003e Va = 450V ; Vg2 = 300V ; Vg = -30V\u003cbr\u003eMeasurements are taken after 10 minutes of preheating the tubes.\u003cbr\u003e\u003cstrong\u003eAverage 100%:\u003c\/strong\u003e Gm = 6.50 ; Ia = 50 mA\u003cbr\u003e\u003cstrong\u003eTEST RESULT:\u003c\/strong\u003e All valves fall at least in the \u003cspan class=\"s1\"\u003e\u003cb\u003eSTRONG\u003c\/b\u003e\u003c\/span\u003e range, with two elements in \u003cspan class=\"s1\"\u003e\u003cb\u003ethe VERY STRONG\u003c\/b\u003e\u003c\/span\u003e area\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eValve 1:\u003c\/strong\u003e Gm = 5.95 ; Ia = 48 mA\u003cbr\u003e\u003cstrong\u003eValve 2:\u003c\/strong\u003e Gm = 5.91 ; Ia = 50 mA\u003cbr\u003e\u003cstrong\u003eValve 3:\u003c\/strong\u003e Gm = 5.15 ; Ia = 44 mA\u003cbr\u003e\u003cstrong\u003eValve 4:\u003c\/strong\u003e Gm = 5.32 ; Ia = 40 mA\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/p\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 Good – Lettering partially eroded, but still legible. Valve body in good condition. See photos for details.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eManufacturing Code:\u003c\/strong\u003e 3227350 → \u003cstrong\u003e322\u003c\/strong\u003e indicates the manufacturer, i.e. Tung-Sol Electric Inc., Newark 4, NJ - \u003cstrong\u003e73\u003c\/strong\u003e → 1973 - \u003cstrong\u003e50\u003c\/strong\u003e → 50th week of the year\u003c\/li\u003e\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\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"MAGNAVOX","offers":[{"title":"Default Title","offer_id":56500199653724,"sku":"03370","price":1049.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_c346cdea-ec97-44a5-a6bd-c3c43fb5e128.jpg?v=1768841757","url":"https:\/\/vacuumtubestreasures.com\/en-hr\/products\/6550-magnavox-by-tung-sol-type-2-4th-generation-amplitrex-matched-quad-strong-made-in-usa-1","provider":"Vacuum Tubes Treasures","version":"1.0","type":"link"}