{"product_id":"6sn7gta-rca-radiotron-matched-pair-black-plates-double-d-side-getter-amplitrex-tested","title":"6SN7GTA RCA Radiotron Matched Pair Black Plates Double D Side Getter AMPLITREX Tested USA 50s","description":"\u003ch3 class=\"p1\"\u003e\u003cstrong\u003e6SN7GTA RCA Radiotron Matched Pair Black Plates Double D Side Getter -\u0026nbsp; Made In USA - 1950s\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp class=\"p1\"\u003e\u003cb\u003eAMPLITREX Tested – VERY STRONG \u003cmeta charset=\"utf-8\"\u003e– \u003cmeta charset=\"utf-8\"\u003eLow Noise \u0026amp; Microphonics \u003cmeta charset=\"utf-8\"\u003e– Vintage American RCA Production\u003c\/b\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eTubes tested on\u0026nbsp;\u003cstrong\u003eAmplitrex AT-1000 Tube tester\u003c\/strong\u003e:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eTest Conditions:\u003c\/strong\u003e\u003cspan\u003e\u0026nbsp;\u003c\/span\u003eVa = 250V, Vg = -8V\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eAverage 100% Gm = 2600 ; Ia = 9.0 mA\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eTest Result:\u003c\/strong\u003e VERY STRONG\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"p1\"\u003e\u003cb\u003eTube #1\u003c\/b\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eSection 1:\u0026nbsp;\u003c\/strong\u003eGm = 2300 ; Ia = 7.6 mA\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eSection 2:\u0026nbsp;\u003c\/strong\u003eGm = 2400 ; Ia = 9.0 mA\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"p1\"\u003e\u003cb\u003eTube #2\u003c\/b\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eSection 1:\u0026nbsp;\u003c\/strong\u003eGm = 2370 ; Ia = 7.2 mA\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eSection 2:\u0026nbsp;\u003c\/strong\u003eGm = 2500 ; Ia = 9.6 mA\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 class=\"p1\"\u003e\u003cb\u003eAdditional tests:\u003c\/b\u003e\u003c\/h3\u003e\n\u003cul\u003e\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\u003cli class=\"p1\"\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eMicrophonics and noise:\u003c\/b\u003e\u003c\/span\u003e Low. Tested and compliant for use in hi-fi equipment and guitar amplifiers, even in the most sensitive audio stages.\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eBalance:\u003c\/b\u003e\u003c\/span\u003e The sections are not perfectly aligned. The tube is indicated for use in hi-fi in non-critical stages (input or driver) and in guitar amplifiers. Not indicated as a phase inverter or in applications that require strict balance between the sections.\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eEmission:\u003c\/b\u003e\u003c\/span\u003e Excellent – Very strong and stable emission, without fluctuations.\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cb\u003eShort circuits \/ Gas:\u003c\/b\u003e\u003cspan class=\"s1\"\u003e absent\u003c\/span\u003e\u003c\/li\u003e\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\u003eCaptivating vintage pair of \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e6SN7GTA RCA Radiotron\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, produced in the United States in the \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e1950s\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e and carefully selected as a \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eMatched Pair\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e. Both specimens share the characteristic \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eBlack Plates with Double D Side Getter\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e construction, a distinctive configuration of the historic American RCA production. The black plates, the particular arrangement of the side getters and the common internal architecture give the pair a homogeneous construction identity, particularly appreciated by connoisseurs of vintage American tubes.\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 highlight a good electrical uniformity between the two specimens. The transconductance of the four sections is between \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e2300 and 2500 µmhos\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, with averages of \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e2350 and 2435 µmhos\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e respectively, compared to the nominal reference of 2600. The anode currents vary from 7.2 to 9.6 mA, with particularly close averages of \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e8.3 and 8.4 mA\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, compared to the reference of 9.0 mA. The overall matching is consistent, although presenting differences in the internal balance of the individual tubes, to be considered in applications that require strict symmetry between the sections.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eBoth tubes have been subjected to careful instrumental checks that confirmed \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003every strong and stable emission\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, without fluctuations, short circuits or presence of gas. The checks also highlighted \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003elow noise and microphonics levels\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, characteristics that are particularly important for use in vintage and compatible modern audio equipment.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e6SN7GTA RCA Black Plates\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e find application in hi-fi preamplifiers, headphone amplifiers and driver stages, especially in circuits that do not require strict symmetry between the sections. The RCA production of the 1950s is traditionally appreciated by audiophiles for a musical presentation generally described as \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003efull-bodied, natural and rich in nuances\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, with an expressive midrange and a pleasant listening fluidity.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe value of this pair lies in the \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eauthenticity of the RCA Black Plates with Double D Side Getter construction\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e and in the documented electrical selection. The code \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e4-35 \/ 274\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e identifies a specimen produced in the 35th week of 1954, while the other, lacking a readable code, presents corresponding construction characteristics, attributable to the same era. The worn screen printing and signs of use testify to their history, without compromising their verified functionality. Two authentic \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003evintage RCA Radiotrons\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, carefully tested and matched, for enthusiasts who wish to rediscover the charm of original American thermionic production.\u003c\/span\u003e\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3 class=\"p1\"\u003e\u003cstrong\u003eConditions\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli class=\"p1\"\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eConditions:\u003c\/b\u003e\u003c\/span\u003e Vintage Tubes - Tested and perfectly functioning. Supplied in our custom box for optimal protection.\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eFunctionality:\u003c\/b\u003e\u003c\/span\u003e Perfectly operational\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eAesthetic conditions:\u003c\/b\u003e\u003c\/span\u003e One tube in sufficient condition, with completely absent screen printing and evident signs of use, the other in Good condition – Partially eroded lettering, but manufacturing code still readable. Tube body in good condition. See photos for details.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eManufacturing codes:\u003c\/strong\u003e\u0026nbsp;\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e4-35 274 → RMA\/EIA Open Date Code → manufactured in the 35th week of 1954 - 274 → Radio Corporation of America, Camden, N. J.\u003c\/li\u003e\n\u003cli\u003e\u003cmeta charset=\"utf-8\"\u003eCode absent. Production attributable approximately to the 1950s based on construction characteristics.\u003cbr\u003e\u003c\/li\u003e\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":59754186834268,"sku":"03912L","price":103.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_478a9fe2-3293-4d7a-88cf-6da2065dce8a.jpg?v=1793799579","url":"https:\/\/vacuumtubestreasures.com\/en-gb\/products\/6sn7gta-rca-radiotron-matched-pair-black-plates-double-d-side-getter-amplitrex-tested","provider":"Vacuum Tubes Treasures","version":"1.0","type":"link"}