{"product_id":"6sn7-gtb-rca-red-logo-amplitrex-matched-pair-black-plates-d-getter-low-noise-mic-tubes","title":"6SN7 GTB RCA Red Logo AMPLITREX Matched Pair Black Plates D Getter Low Noise \u0026 Mic Tubes","description":"\u003ch3 class=\"p1\"\u003e\u003cstrong\u003e6SN7 GTB RCA Red Logo AMPLITREX Matched Pair Black Plates D Getter - Made In USA - 1960s\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp class=\"p1\"\u003e\u003cb\u003eAMPLITREX Tested – VERY STRONG – Low Noise \u0026amp; Microphonics\u003c\/b\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eTubes tested on \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 Va = 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 #1\u003c\/b\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eSection 1: \u003c\/strong\u003eGm = 2400 ; Ia = 9.2 mA\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eSection 2: \u003c\/strong\u003eGm = 2500 ; Ia = 10.0 mA\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp class=\"p1\"\u003e\u003cb\u003eTube #2\u003c\/b\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eSection 1: \u003c\/strong\u003eGm = 2400 ; Ia = 8.8 mA\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eSection 2: \u003c\/strong\u003eGm = 2500 ; Ia = 9.4 mA\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003ch3 class=\"p1\"\u003e\u003cb\u003eDescription\u003c\/b\u003e\u003c\/h3\u003e\n\u003cp\u003eA prized matched pair of \u003cstrong\u003e6SN7GTB RCA Red Logo\u003c\/strong\u003e, manufactured in the USA in the mid-1960s, featuring the sought-after \u003cstrong\u003eBlack Plates with D Getter\u003c\/strong\u003e construction. Both tubes belong to the same RCA production run and represent a configuration that is increasingly appealing to those seeking authentic vintage American 6SN7s selected for audio use.\u003c\/p\u003e\n\u003cp\u003eRCA's construction with \u003cstrong\u003eBlack Plates\u003c\/strong\u003e and \u003cstrong\u003eD Getter\u003c\/strong\u003e is particularly valued for its robustness, reliability, and sonic consistency. Tubes from this period retain many of the construction characteristics of earlier RCA productions, combined with the greater uniformity typical of 1960s manufacturing.\u003c\/p\u003e\n\u003cp\u003eThe pair has been carefully tested and selected in our laboratory using the \u003cstrong\u003eAmplitrex AT-1000 Tube Tester\u003c\/strong\u003e, achieving a \u003cstrong\u003eVERY STRONG\u003c\/strong\u003e classification. Both tubes were found to have \u003cstrong\u003eLow Noise \u0026amp; Microphonics\u003c\/strong\u003e and exhibit excellent electrical alignment, with transconductance values perfectly matching between the two samples and well-balanced internal sections.\u003c\/p\u003e\n\u003cp\u003eSonically, RCA Black Plate tubes are known for full, natural, and authoritative reproduction, with solid and controlled bass, a rich and musical midrange, soft yet well-defined treble, and a broad and stable soundstage. The overall character is balanced, dynamic, and refined, with the typical warmth of the best American RCA productions.\u003c\/p\u003e\n\u003cp\u003eIdeal for hi-fi preamplifiers, driver stages, phase splitters, headphone amplifiers, and all equipment compatible with \u003cstrong\u003e6SN7GT \/ 6SN7GTB\u003c\/strong\u003e that requires a high-quality matched pair.\u003c\/p\u003e\n\u003cp\u003eThe tubes are \u003cstrong\u003eused\u003c\/strong\u003e, carefully tested, and fully functional. Aesthetic conditions are \u003cstrong\u003egood\u003c\/strong\u003e, with partially faded but still legible logos and the tube body in good overall condition.\u003c\/p\u003e\n\u003cp\u003eA prized matched pair of authentic \u003cstrong\u003eRCA 6SN7GTB Red Logo Black Plates\u003c\/strong\u003e, genuinely tested and selected by \u003cstrong\u003eVacuum Tubes Treasures\u003c\/strong\u003e, ideal for those seeking manufacturing quality, musicality, and reliability in vintage American production.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3 class=\"p1\"\u003e\u003cb\u003eAdditional Tests:\u003c\/b\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\n\u003cli class=\"p1\"\u003e\n\n\u003cspan class=\"s1\"\u003e\u003cb\u003eMicrophonics and Noise:\u003c\/b\u003e\u003c\/span\u003e Low. Tested and suitable for use in hi-fi equipment and guitar amplifiers, even in 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 Good. The sections show consistent balance, fully compatible for use in hi-fi and musical amplifiers, in all applications where absolute symmetry between sections is not required.\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\u003eShorts \/ 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\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 Vintage Tubes - Tested and fully functional. 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 Fully 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 Good – Labels partially faded, but still legible. Tube body in good condition. See photos for details.\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eManufacturing Code:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003eAV → two-letter code → November 1965 production → Radio Corporation of America, Camden, N. J.\u003cmeta charset=\"utf-8\"\u003e\n\n\n\u003c\/li\u003e\n\n\u003cli\u003eBG → two-letter code → October 1966 production → Radio Corporation of America, Camden, N. J.\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 durability\" 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":58795735712092,"sku":"03755","price":119.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/3_70d6af9f-e34b-445b-9f14-bfab8bd598bb.jpg?v=1787657876","url":"https:\/\/vacuumtubestreasures.com\/en-lt\/products\/6sn7-gtb-rca-red-logo-amplitrex-matched-pair-black-plates-d-getter-low-noise-mic-tubes","provider":"Vacuum Tubes Treasures","version":"1.0","type":"link"}