{"product_id":"6v6gt-rca-black-plates-smoked-glass-dd-getter-closely-tested-pair-tubes-usa-1950s","title":"6V6GT RCA Black Plates Smoked Glass DD Getter Closely Matched Pair Tubes USA 1950s","description":"\u003ch3\u003e\u003cstrong\u003e6V6GT RCA Black Plates Smoked Glass DD Bottom Getter - Closely Tested Pair Tubes - Made in USA 1950s\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cstrong\u003eAMPLITREX Tested –\u003cspan\u003e STRONG - Vintage American RCA 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 STRONG\u003c\/li\u003e\n\n\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 = 4.29 ; Ia = 40.8 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 = 4.14 ; Ia = 34.6 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\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e Low. 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 Strong – Strong and steady emission, suitable for any application.\u003c\/span\u003e\u003c\/li\u003e\n\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eShorts 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\u003eSelected pair of \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e6V6GT RCA Made in USA\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, belonging to the prestigious American production of the \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e1950s\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e. Both feature the sought-after construction with \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eblack plates, smoked glass, and double D bottom getter\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, features particularly appreciated by connoisseurs of the early RCA 6V6GTs.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eOne tube bears the code \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e5-43\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, which dates its manufacture to the \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e43rd week of 1955\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e. The \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eYJL\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e code present on the other cannot be deciphered with certainty, but the structural configuration confirms it belongs to the RCA production of the same historical period.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe tubes were carefully verified on an \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eAmplitrex AT-1000\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e. Tube 1 recorded \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eGm 4.29 mA\/V and Ia 40.8 mA\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, while Tube 2 measures \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eGm 4.14 mA\/V and Ia 34.6 mA\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e. The transconductance is extremely close, with a deviation of less than \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e4%\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, and both units reach or exceed the nominal reference value.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe plate current shows a more marked difference, equal to about \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e16%\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e. The pair is therefore closely matched by transconductance but should not be considered a \u003c\/span\u003e\u003cem\u003e\u003cspan\u003eprecision current matched pair\u003c\/span\u003e\u003c\/em\u003e\u003cspan\u003e. It is particularly recommended for amplifiers with individual bias adjustment and for applications where absolute coincidence of quiescent current is not required.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eBoth tubes showed \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003estrong and steady emission\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, low microphonics, and no gas or shorts. They are suitable for hi-fi power stages, guitar amplifiers, and vintage equipment compatible with the 6V6GT.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eIn terms of sound, 1950s RCA black plates are generally appreciated for a \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003efull-bodied, musical, and natural\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e presentation, with a rich midrange, authoritative low frequencies, and well-defined high frequencies without being aggressive.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThese are \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eused, tested, and perfectly functional vintage tubes\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, with well-preserved lettering and excellent aesthetic conditions. Supplied in custom Vacuum Tubes Treasures boxes.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eA highly appealing 1950s RCA pair, selected for \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eclosely matched transconductance, authentic black plate construction, and characteristic double D bottom getter\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e.\u003c\/span\u003e\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eConditions:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eStatus:\u003c\/strong\u003e Vintage Tubes - Tested and perfectly functional. Supplied 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 well preserved, minimal signs of aging. See photos for details.\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eManufacture code:\u003c\/strong\u003e \u003cmeta charset=\"utf-8\"\u003emanufactured by \u003cmeta charset=\"utf-8\"\u003eRadio Corporation of America, Camden, N. J. - one tube 5-43 → RMA\/EIA Open Date Code → manufactured the 43rd week of 1955 - one tube YJL → code cannot be deciphered. Production attributable to the 50s based on the structural features.\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=\"Why our tubes are different – the VTT protocol that improves sound, reliability and longevity\" rel=\"noopener\" target=\"_blank\"\u003e\u003cstrong\u003eDiscover why our tubes are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"RCA","offers":[{"title":"Default Title","offer_id":59247136244060,"sku":"03836T","price":1313.0,"currency_code":"NOK","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/2_6c4ab5ba-0c21-4885-aa38-3d4520e50f5c.jpg?v=1790153151","url":"https:\/\/vacuumtubestreasures.com\/en-no\/products\/6v6gt-rca-black-plates-smoked-glass-dd-getter-closely-tested-pair-tubes-usa-1950s","provider":"Vacuum Tubes Treasures","version":"1.0","type":"link"}