{"product_id":"6sn7gta-nos-sylvania-chrome-top-matched-sextet-same-production-code-low-noise-microphonics-amplitrex-tested","title":"6SN7GTA NOS SYLVANIA Chrome Top Matched Sextet - Same Production Code - Low Noise \u0026 Microphonics - AMPLITREX Tested","description":"\u003ch3 data-pm-slice=\"1 3 []\"\u003e\u003cstrong\u003e\u003cspan\u003e6SN7GTA NOS SYLVANIA – Short Base Chrome Top – Black Plates – Matched Sextet – Made in USA 1955\u003c\/span\u003e\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eAMPLITREX Tested – VERY STRONG – Matched Sextet – Low Noise \u0026amp; Microphonics\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003e\u003cspan\u003eTest Results:\u003c\/span\u003e\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cspan\u003eTested on \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eAmplitrex AT-1000 Tube Tester\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e:\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003e\u003cspan\u003eTest Conditions:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Va = 250V; Vg = -8V\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003e\u003cspan\u003e100% Average:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Gm = 2600; Ia = 9.0 mA\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003e\u003cspan\u003eTest Result:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e VERY STRONG\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003e\u003cspan\u003eSextet Range on Tube Averages:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Gm = 2600–2600; Ia = 7.6–7.8 mA\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003e\u003cspan\u003eMatched Score:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e 2.60 – Excellent Match\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eTube #6\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003e\u003cspan\u003eSection 1:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Gm = 2600; Ia = 7.6 mA\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003e\u003cspan\u003eSection 2:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Gm = 2600; Ia = 7.6 mA\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eTube #37\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003e\u003cspan\u003eSection 1:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Gm = 2600; Ia = 7.8 mA\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003e\u003cspan\u003eSection 2:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Gm = 2600; Ia = 7.4 mA\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eTube #35\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003e\u003cspan\u003eSection 1:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Gm = 2600; Ia = 7.6 mA\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003e\u003cspan\u003eSection 2:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Gm = 2600; Ia = 7.8 mA\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eTube #4\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003e\u003cspan\u003eSection 1:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Gm = 2500; Ia = 7.4 mA\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003e\u003cspan\u003eSection 2:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Gm = 2700; Ia = 8.0 mA\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eTube #7\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003e\u003cspan\u003eSection 1:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Gm = 2600; Ia = 7.6 mA\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003e\u003cspan\u003eSection 2:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Gm = 2600; Ia = 8.0 mA\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eTube #8\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003e\u003cspan\u003eSection 1:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Gm = 2600; Ia = 7.6 mA\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003e\u003cspan\u003eSection 2:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Gm = 2600; Ia = 8.0 mA\u003c\/span\u003e\n\n\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.\u003cbr\u003e\n\n\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 none\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 sextet\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, produced in the United States in \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e1955\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e and carefully selected as a \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eMatched Sextet\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e. All six tubes share the identical manufacturing code \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e288 \/ 513\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, dating back to the 13th week of 1955, and feature the characteristic \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eShort Base Chrome Top with Black Plates\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e construction. A particularly interesting set due to its construction uniformity and its origin from the same 1950s Sylvania American production run.\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 reveal an exceptionally precise match. All six tubes have an identical average transconductance of \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e2600 µmhos\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, corresponding to the nominal reference, while the average anode currents are concentrated in the extremely narrow range of \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e7.6–7.8 mA\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e. Considering the individual sections, the transconductance varies from 2500 to 2700 µmhos and the anode current from 7.4 to 8.0 mA. The \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eMatched Score of 2.60\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e confirms the excellent overall uniformity, a particularly significant feature for a group of six vintage tubes.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eEach tube passed \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e48 hours of burn-in and stability testing\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, demonstrating very strong and consistent emission, without fluctuations, short circuits, or gas. The tests also confirmed very low noise and microphonics levels, with special \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eGreen Dot and Gray Dot\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e selection \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003everified \u003c\/span\u003e\u003cspan\u003eusing the \u003c\/span\u003e\u003cspan\u003eAmplitrex \u003c\/span\u003e\u003cspan\u003eAT-1000.\u003c\/span\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 Sylvania internal code. 513 - 13th week of 1955 (March 1955).\u003c\/li\u003e\n\n\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\u003c\/strong\u003e\u003c\/p\u003e","brand":"SYLVANIA","offers":[{"title":"Default Title","offer_id":59659409916252,"sku":"03901","price":519.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_0bf4a4cf-7267-49de-b155-9205d7f7b762.jpg?v=1793112520","url":"https:\/\/vacuumtubestreasures.com\/en-bg\/products\/6sn7gta-nos-sylvania-chrome-top-matched-sextet-same-production-code-low-noise-microphonics-amplitrex-tested","provider":"Vacuum Tubes Treasures","version":"1.0","type":"link"}