{"product_id":"6v6gt-nos-national-union-matched-pair-smoked-glass-black-plates-foil-getter-made-in-usa-50s","title":"6V6GT NOS National Union Matched Pair Smoked Glass Black Plates Foil Getter Made in USA '50s","description":"\u003cp class=\"p1\"\u003e\u003cb\u003e6V6GT NOS NU (National Union) – Smoked Glass – Black Plates – Foil Getter – Matched Pair – Made in USA ‘50s\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e\u003cb\u003eVACUUM TUBES TREASURES Selection – Low Noise \u0026amp; Microphonics\u003c\/b\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cb\u003eGeneral Description\u003c\/b\u003e\u003c\/h3\u003e\n\u003cp class=\"p1\"\u003eWe offer a fascinating \u003cspan class=\"s1\"\u003e\u003cb\u003ematched pair of 6V6GT NOS National Union (NU)\u003c\/b\u003e\u003c\/span\u003e, manufactured in the USA in the 1950s, one of the most iconic eras for vacuum tube production.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eThese tubes are distinguished by a construction typical of high-quality American manufacturing:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"p1\"\u003e\u003cb\u003eSmoked Glass\u003c\/b\u003e\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cb\u003eBlack Plates\u003c\/b\u003e\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cb\u003eFoil Getter\u003c\/b\u003e\u003c\/li\u003e\n\u003cli class=\"p1\"\u003erobust and refined internal structure\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"p1\"\u003eThe \u003cspan class=\"s1\"\u003e\u003cb\u003eNational Union\u003c\/b\u003e\u003c\/span\u003e brand is historically recognized for productions with a distinctive sonic character, often highly valued for musicality and naturalness.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eThe tubes have been selected as a \u003cspan class=\"s1\"\u003e\u003cb\u003eMatched Pair within NOS tolerance (Ia 10% \/ Gm 20%)\u003c\/b\u003e\u003c\/span\u003e, ensuring consistent and reliable electrical performance.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e⚠️ The tubes have \u003cspan class=\"s1\"\u003e\u003cb\u003edifferent manufacturing codes\u003c\/b\u003e\u003c\/span\u003e, but are perfectly compatible and correctly matched electrically.\u003c\/p\u003e\n\u003ch3\u003e\u003cb\u003eSonic Characteristics\u003c\/b\u003e\u003c\/h3\u003e\n\u003cp class=\"p1\"\u003eThe 1950s National Union 6V6GTs offer a warm, musical, and deeply engaging sonic signature.\u003c\/p\u003e\n\u003cp class=\"p3\"\u003e\u003cb\u003eBass\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eSoft yet present, with good articulation and naturalness.\u003c\/p\u003e\n\u003cp class=\"p3\"\u003e\u003cb\u003eMids\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eAn absolute strength: full, textured, and rich in harmonics, with extremely realistic vocal reproduction.\u003c\/p\u003e\n\u003cp class=\"p3\"\u003e\u003cb\u003eHighs\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eSweet and rounded, never aggressive, perfect for extended listening sessions.\u003c\/p\u003e\n\u003cp class=\"p3\"\u003e\u003cb\u003eDynamics\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eProgressive and musical, with a fluid response that prioritizes timbral coherence.\u003c\/p\u003e\n\u003cp class=\"p3\"\u003e\u003cb\u003eSoundstage\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eNatural and believable, with good depth and excellent separation.\u003c\/p\u003e\n\u003ch3\u003e\u003cb\u003e🎧 Use in Hi-Fi Amplifiers\u003c\/b\u003e\u003c\/h3\u003e\n\u003cp class=\"p1\"\u003ePerfect for:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"p1\"\u003esingle-ended and push-pull amplifiers based on \u003cspan class=\"s1\"\u003e\u003cb\u003e6V6\u003c\/b\u003e\u003c\/span\u003e\u003c\/li\u003e\n\u003cli class=\"p1\"\u003ehi-fi systems oriented towards musicality and timbral realism\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"p1\"\u003eThanks to selection and low noise, they are also suitable for sensitive configurations.\u003c\/p\u003e\n\u003ch3\u003e\u003cb\u003e🎸 Use in Musical Applications\u003c\/b\u003e\u003c\/h3\u003e\n\u003cp class=\"p1\"\u003eIdeal for:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"p1\"\u003evintage-style guitar amplifiers\u003c\/li\u003e\n\u003cli class=\"p1\"\u003etube preamps\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"p1\"\u003eThey offer:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"p1\"\u003esoft and progressive breakup\u003c\/li\u003e\n\u003cli class=\"p1\"\u003erich harmonic response\u003c\/li\u003e\n\u003cli class=\"p1\"\u003ewarm and three-dimensional sound\u003c\/li\u003e\n\u003c\/ul\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\u003eNational Union – Made in USA – 1950s\u003c\/b\u003e\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cb\u003eSmoked Glass – Black Plates – Foil Getter\u003c\/b\u003e\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cb\u003eMatched Pair (NOS tolerance)\u003c\/b\u003e\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cb\u003eSelected and tested in our laboratory\u003c\/b\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"p3\"\u003e\u003cspan class=\"s2\"\u003e⚠️\u0026nbsp;\u003c\/span\u003e\u003cb\u003eCosmetic conditions:\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p4\"\u003eGood – legends partially eroded but still legible.\u003c\/p\u003e\n\u003cp class=\"p4\"\u003eOne tube has a \u003cspan class=\"s3\"\u003e\u003cb\u003ecrack on the plastic base\u003c\/b\u003e\u003c\/span\u003e, visible in the photos.\u003c\/p\u003e\n\u003cp class=\"p4\"\u003eThis is an exclusively cosmetic defect that \u003cspan class=\"s3\"\u003e\u003cb\u003edoes not affect functionality\u003c\/b\u003e\u003c\/span\u003e, as verified in tests.\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\u003cstrong\u003eTest Conditions:\u003c\/strong\u003e\u003cspan\u003e \u003cmeta charset=\"utf-8\"\u003eVa = 250V; Vg2 = 250V; Vg = -12.5V\u0026nbsp;\u003c\/span\u003e\u003c\/li\u003e\n\u003cli style=\"font-weight: bold;\"\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 \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\u003eTube 1:\u003c\/strong\u003e \u003cmeta charset=\"utf-8\"\u003e\u003cspan\u003eGm = 4.3 ; Ia = 41.6 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 = 3.8 ; Ia = 45.8 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 compliant 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 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-end=\"371\" data-start=\"221\"\u003e\u003cstrong data-end=\"233\" data-start=\"223\"\u003eCondition:\u003c\/strong\u003e Vintage Tubes - Tested and perfectly functional. Supplied in our custom box for optimal protection.\u0026nbsp;\u003c\/li\u003e\n\u003cli data-end=\"456\" data-start=\"372\"\u003e\u003cstrong data-end=\"391\" data-start=\"374\"\u003eFunctionality:\u003c\/strong\u003e Perfectly operational, with excellent test results.\u003c\/li\u003e\n\u003cli data-end=\"672\" data-start=\"457\"\u003e\u003cstrong data-end=\"484\" data-start=\"459\"\u003eCosmetic conditions:\u003c\/strong\u003e Good – Legends partially eroded, but still legible.\u0026nbsp;\u003cmeta charset=\"utf-8\"\u003e\n\u003cp class=\"p4\"\u003eOne tube has a\u003cspan class=\"s3\"\u003e\u003cb\u003e\u0026nbsp;crack on the plastic base\u003c\/b\u003e\u003c\/span\u003e, visible in the photos.\u0026nbsp;This is an exclusively cosmetic defect that \u003cspan class=\"s3\"\u003e\u003cb\u003edoes not affect functionality\u003c\/b\u003e\u003c\/span\u003e, as verified in tests.\u0026nbsp;See photos for details.\u003c\/p\u003e\n\u003cstrong data-end=\"703\" data-start=\"675\"\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong data-end=\"703\" data-start=\"675\"\u003eManufacturing code:\u0026nbsp;\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e51-39 \u003cmeta charset=\"utf-8\"\u003e→ RMA\/EIA Open Date Code → manufactured in the 39th week of 1951\u003c\/li\u003e\n\u003cli\u003eKR S \u003cmeta charset=\"utf-8\"\u003e→ undecipherable, identifiable by construction characteristics. 1950s\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=\"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\/p\u003e","brand":"NATIONAL UNION","offers":[{"title":"Default Title","offer_id":57247845744988,"sku":"03496V","price":149.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/2_1fcb0462-e3f1-4e74-bd48-2d7c31042b12.jpg?v=1775117338","url":"https:\/\/vacuumtubestreasures.com\/en-bg\/products\/6v6gt-nos-national-union-matched-pair-smoked-glass-black-plates-foil-getter-made-in-usa-50s","provider":"Vacuum Tubes Treasures","version":"1.0","type":"link"}