{"product_id":"6sn7gta-nos-sylvania-chrome-top-matched-quad-same-production-code-low-noise-microphonics-amplitrex-tested","title":"6SN7GTA NOS SYLVANIA Chrome Top Matched Quad - Same Production Code - Low Noise \u0026 Microphonics - AMPLITREX Tested","description":"\u003ch3 class=\"p1\"\u003e\u003cb\u003e6SN7GTA NOS SYLVANIA – \u003cmeta charset=\"utf-8\"\u003e \u003cspan\u003eShort \u003c\/span\u003e\u003cspan\u003eBase \u003c\/span\u003e\u003cspan\u003eChrome \u003c\/span\u003e\u003cspan\u003eTop\u003c\/span\u003e – Matched Quad – Same Data Codes – Made in USA 1955\u003c\/b\u003e\u003c\/h3\u003e\n\u003cp class=\"p1\"\u003e\u003cb\u003eAMPLITREX Tested – VERY STRONG – \u003cmeta charset=\"utf-8\"\u003e \u003cspan\u003eGreen Dot \u0026amp; Gray Dot \u003cmeta charset=\"utf-8\"\u003e– \u003c\/span\u003eLow Noise \u0026amp; Microphonics\u003c\/b\u003e\u003c\/p\u003e\n\u003ch3 data-start=\"3046\" data-end=\"3436\"\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eTubes tested on an \u003cstrong\u003eAmplitrex AT-1000 Tube Tester\u003c\/strong\u003e:\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eTest Conditions:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eVa = 250V, Vg = -8V\u003c\/li\u003e\n\n\u003cli\u003e\u003cstrong\u003eAverage 100% Gm = 2600 ; Ia = 9.0 mA\u003c\/strong\u003e\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 class=\"p1\"\u003e\u003cb\u003eTube #15\u003c\/b\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli class=\"p1\"\u003eSection 1: Gm = \u003cmeta charset=\"utf-8\"\u003e2600 ; Ia = 8.2 mA\u003c\/li\u003e\n\n\u003cli class=\"p1\"\u003eSection 2: Gm = 2600 ; Ia = 8.0 mA\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp class=\"p1\"\u003e\u003cb\u003eTube #22\u003c\/b\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli class=\"p1\"\u003eSection 1: Gm = 2500 ; Ia = 8.0 mA\u003c\/li\u003e\n\n\u003cli class=\"p1\"\u003eSection 2: Gm = 2700 ; Ia = 8.4 mA\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp class=\"p1\"\u003e\u003cb\u003eTube #5\u003c\/b\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli class=\"p1\"\u003eSection 1: Gm = 2600 ; Ia = 8.4 mA\u003c\/li\u003e\n\n\u003cli class=\"p1\"\u003eSection 2: Gm = 2600 ; Ia = 8.2 mA\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp class=\"p1\"\u003e\u003cb\u003eTube #39\u003c\/b\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli class=\"p1\"\u003eSection 1: Gm = 2620 ; Ia = 8.6 mA\u003c\/li\u003e\n\n\u003cli class=\"p1\"\u003eSection 2: Gm = \u003cmeta charset=\"utf-8\"\u003e2600 ; Ia = 7.8 mA\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003ch3 class=\"p1\"\u003e\u003cb\u003eAdditional Tests:\u003c\/b\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\n\u003cli class=\"p1\"\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eBurn-in \/ Stability Test:\u003c\/b\u003e 48h – OK\u003c\/span\u003e\u003c\/li\u003e\n\n\u003cli class=\"p1\"\u003e\n\n\u003cspan class=\"s1\"\u003e\u003cb\u003eMicrophonics and noise:\u003c\/b\u003e\u003c\/span\u003e Very Low. Tested and suitable for use in hi-fi equipment and guitar amplifiers, including the most sensitive audio stages.\u003c\/li\u003e\n\n\u003cli class=\"p1\"\u003e\n\n\u003cspan class=\"s1\"\u003e\u003cb\u003eBalance:\u003c\/b\u003e\u003c\/span\u003e Very good. The sections are consistent and well-matched, making the tube suitable for use as a phase inverter in hi-fi and instrument applications.\u003c\/li\u003e\n\n\u003cli class=\"p1\"\u003e\n\n\u003cspan class=\"s1\"\u003e\u003cb\u003eEmission:\u003c\/b\u003e\u003c\/span\u003e Excellent – Very strong and stable emission, without fluctuations.\u003c\/li\u003e\n\n\u003cli class=\"p1\"\u003e\n\n\u003cb\u003eShort Circuits \/ Gas:\u003c\/b\u003e\u003cspan class=\"s1\"\u003e absent\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003ch3 class=\"p1\"\u003e\u003cb\u003eDescription\u003c\/b\u003e\u003c\/h3\u003e\n\u003cp data-pm-slice=\"1 1 []\"\u003e\u003cspan\u003eExceptional \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eNOS 6SN7GTA Sylvania quad\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, produced in the United States in 1955 and carefully selected as a \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eMatched Quad\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e. All four specimens share the same manufacturing code and feature the sought-after \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eShort Base Chrome Top\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e construction, with \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eblack plates and top getter\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, a characteristic of the prestigious Sylvania American production of the 1950s.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe measurements performed with the \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eAmplitrex AT-1000\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e show very consistent values: the individual sections have a transconductance between \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eGm 2500 and 2700\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, while the anode current is within the narrow range of \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e7.8–8.6 mA\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e. These results confirm an electrically well-matched quad, with balanced sections and consistent performance across all four specimens.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eEach tube was subjected to \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e48 hours of burn-in and stability testing\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, in addition to specific noise and microphonics checks. The \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eGreen Dot and Gray Dot\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e selection identifies specimens characterized by \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003every low noise and microphonics\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, suitable even for the most sensitive audio stages.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThanks to its excellent electrical uniformity, this quad is particularly suitable for \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003epreamplifiers, headphone amplifiers, balanced circuits, driver stages, buffers, and phase inverters\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, as well as high-end hi-fi equipment requiring four 6SN7 tubes with consistent characteristics.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThese 6SN7GTAs express the traditionally appreciated qualities of Sylvania production: an \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eopen, dynamic, and natural presentation\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, accompanied by excellent transparency, definition, and control.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eA \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003erare matched NOS quad\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, originating from the same production batch from the \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e13th week of 1955\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, intended for the most demanding enthusiasts and collectors seeking authentic American Sylvania tubes that are consistent and carefully selected.\u003c\/span\u003e\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3 class=\"p1\"\u003e\u003cstrong\u003eCondition\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\n\u003cli class=\"p1\"\u003e\n\n\u003cspan class=\"s1\"\u003e\u003cb\u003eCondition:\u003c\/b\u003e\u003c\/span\u003e NOS - New Old Stock - Tested and working - Supplied in our custom box for optimal protection.\u003c\/li\u003e\n\n\u003cli class=\"p1\"\u003e\n\n\u003cspan class=\"s1\"\u003e\u003cb\u003eFunctionality:\u003c\/b\u003e\u003c\/span\u003e Perfectly operational\u003c\/li\u003e\n\n\u003cli class=\"p1\"\u003e\n\n\u003cspan class=\"s1\"\u003e\u003cb\u003eAesthetic condition:\u003c\/b\u003e\u003c\/span\u003e Excellent – Markings optimally preserved, minimal signs of age. See photos for details.\u003c\/li\u003e\n\n\u003cli class=\"p1\"\u003e\n\n\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003eSpecial \u003c\/strong\u003e\u003cspan\u003e\u003cstrong\u003eselection:\u003c\/strong\u003e \u003c\/span\u003e\u003cstrong\u003e\u003cmeta charset=\"utf-8\"\u003e\u003c\/strong\u003e\u003cspan\u003eGreen \u003c\/span\u003e\u003cspan\u003eDot \u003c\/span\u003e\u003cspan\u003eand \u003c\/span\u003e\u003cspan\u003eGray \u003c\/span\u003e\u003cspan\u003eDot, \u003c\/span\u003e\u003cspan\u003ewith \u003c\/span\u003e\u003cspan\u003elow \u003c\/span\u003e\u003cspan\u003enoise \u003c\/span\u003e\u003cspan\u003eand \u003c\/span\u003e\u003cspan\u003emicrophonics \u003c\/span\u003e\u003cspan\u003everified \u003c\/span\u003e\u003cspan\u003eusing \u003c\/span\u003e\u003cspan\u003eAmplitrex \u003c\/span\u003e\u003cspan\u003eAT-1000.\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eManufacturing code:\u003c\/strong\u003e Sylvania Electric Products Inc., USA – original marking on the base 288 \/ 513. 288 is the internal Sylvania code. 513 - 13th week of 1955 (March 1955).\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 longevity\" 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":"SYLVANIA","offers":[{"title":"Default Title","offer_id":59658837721436,"sku":"03900","price":4063.0,"currency_code":"SEK","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_9bdc68a0-c003-4b91-b8d6-06233f808667.jpg?v=1793096855","url":"https:\/\/vacuumtubestreasures.com\/en-se\/products\/6sn7gta-nos-sylvania-chrome-top-matched-quad-same-production-code-low-noise-microphonics-amplitrex-tested","provider":"Vacuum Tubes Treasures","version":"1.0","type":"link"}