{"product_id":"6v6gt-nos-gm-by-sylvania-black-plate-foil-getter-amplitrex-tested-tube-usa-1956","title":"6V6GT NOS GM by Sylvania Black Plate Foil Getter AMPLITREX Tested Tube USA 1956","description":"\u003ch3\u003e\u003cstrong\u003e6V6GT NOS GM by Sylvania Black Plate Foil Getter Tube Made in USA 1956\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cstrong\u003eAMPLITREX Tested –\u003cspan\u003e VERY STRONG - Vintage American Sylvania Production\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\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 \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\u003e100% Average:\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\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cstrong\u003eTube:\u003c\/strong\u003e \u003cmeta charset=\"utf-8\"\u003e\u003cspan\u003eGm = 4.41 ; Ia = 46.4 mA\u003c\/span\u003e\u003c\/p\u003e\n\u003cdiv\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/div\u003e\n\u003cul\u003e\n\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e Standard. Tested and compliant for use in hi-fi equipment 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\u003eShort Circuits and GAS:\u003c\/strong\u003e None.\u003c\/span\u003e\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cspan\u003eAuthentic \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e6V6GT NOS – New Old Stock\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, marketed as a \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eGM Genuine Parts\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e replacement and manufactured in the United States by \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eSylvania Electric Products Inc.\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e A private-label production of great historical charm, intended for the General Motors spare parts network but built to the standards of the prestigious Sylvania factory in Emporium, Pennsylvania.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe code \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e312 652\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e unequivocally identifies Sylvania and dates the manufacture to the \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e52nd week of 1956\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e. The tube features the sought-after American construction with \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eblack plate and foil getter\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, accompanied by the characteristic GM Genuine Parts branded base and original markings that are excellently preserved.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eTested on an \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eAmplitrex AT-1000\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, it recorded \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eGm 4.41 mA\/V and Ia 46.4 mA\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, exceeding the nominal reference values in both transconductance and plate current. The result corresponds to approximately \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e108% for Gm and 103% for Ia\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, confirming \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003every strong, stable, and fully efficient\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e emission.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eDuring testing, no fluctuations, leakage, gas, or short circuits were detected. Microphonics are within the standard values expected for a power tube and were found to be compliant for use in vintage hi-fi amplifiers, guitar amplifiers, and other equipment designed for the 6V6GT.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eRegarding sound, American 1950s Sylvania 6V6GTs are generally appreciated for an \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eopen, dynamic, and natural\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e presentation, with well-articulated mids, controlled low frequencies, and a defined high end. A performance capable of combining energy, clarity, and musicality, particularly interesting in single-ended amplifiers or as an element to complete a matched pair.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eOffered as \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eNOS – New Old Stock\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, tested and perfectly functional, it is in excellent aesthetic condition, with crisp lettering and only minimal signs of age. It comes in a custom Vacuum Tubes Treasures box.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eA particularly charming 1956 6V6GT, enhanced by \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eGM Genuine Parts branding, authentic Sylvania black plate construction, and above-nominal Amplitrex values\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e.\u003c\/span\u003e\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eCondition:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eStatus:\u003c\/strong\u003e NOS - New Old Stock - Tested and functional - Provided in our custom box for optimal protection. \u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eFunctionality:\u003c\/strong\u003e Perfectly operational.\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eAesthetic condition:\u003c\/strong\u003e Excellent – Lettering excellently preserved, minimal signs of age. See photos for details.\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eManufacturing code:\u003c\/strong\u003e 312 652 → 312 Sylvania Electric Products Inc., Emporium, Pa. - 652 → 6 (of three digits) → 1956 - 52 → 52nd week of the year\u003c\/li\u003e\n\n\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\u003eFind out why our tubes are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"RAYTHEON","offers":[{"title":"Default Title","offer_id":59268309156188,"sku":"03839T","price":762.0,"currency_code":"NOK","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_a123146f-4931-4c7c-b3a6-b67e1b4a1dcb.jpg?v=1790262278","url":"https:\/\/vacuumtubestreasures.com\/en-no\/products\/6v6gt-nos-gm-by-sylvania-black-plate-foil-getter-amplitrex-tested-tube-usa-1956","provider":"Vacuum Tubes Treasures","version":"1.0","type":"link"}