{"product_id":"6sn7gt-rca-radiotron-matched-pair-silver-logo-black-plates-d-getter-amplitrex-tested-low-noise-mic-tubes","title":"6SN7GT RCA Radiotron Matched Pair Silver Logo Black Plates D Getter AMPLITREX Tested Low Noise \u0026 Mic Tubes","description":"\u003ch3 class=\"p1\"\u003e\u003cstrong\u003e6SN7GT RCA Radiotron Matched Pair Silver Logo Black Plates D Getter -  Made In USA - 1950s\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp class=\"p1\"\u003e\u003cb\u003eAMPLITREX Tested – VERY STRONG – Low 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 \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\u003cspan\u003e \u003c\/span\u003eVa = 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 = 2500 ; Ia = 8.2 mA\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eSection 2: \u003c\/strong\u003eGm = 2500 ; Ia = 7.8 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 = 2600 ; Ia = 7.6 mA\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eSection 2: \u003c\/strong\u003eGm = 2300 ; Ia = 8.0 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 data-pm-slice=\"1 1 []\"\u003e\u003cspan\u003eInteresting vintage pair of \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e6SN7GT 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 feature the characteristic \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eBlack Plates with D Getter\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e construction, a configuration particularly appreciated in American RCA production. The famous silver \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eRCA Radiotron\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e screen printing, still clearly visible on one of the specimens, recalls the charm of the original tubes from this period. The manufacturing markings date the pair to \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e1954\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, with a completely legible date on one tube and partially preserved on the other.\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 confirm overall well-matched electrical characteristics. The transconductance of the four sections ranges between \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e2300 and 2600 µmhos\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, with averages of \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e2500 and 2450 µmhos\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e for the respective tubes, close to the nominal reference of 2600. The anode currents range from 7.6 to 8.2 mA, with averages of \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e8.0 and 7.8 mA\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, compared to the reference of 9.0 mA. Although there are some differences between the individual sections, the pair shows a \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003egood overall match\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, particularly evident in the closeness of the average anode currents.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eBoth tubes have been carefully checked for \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eemission stability, noise, and microphonics\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, with results confirming strong and stable emission, low noise levels, and no shorts or gas. Important checks to assess the actual condition of used vintage tubes and select reliable specimens for even sensitive audio applications.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e6SN7GT RCA Black Plates\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e find use in hi-fi preamplifiers, headphone amplifiers, driver stages, and compatible phase inverter circuits. This American production 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 balanced reproduction, characteristics that continue to fuel interest in tube listening.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe charm of this pair lies in its \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003ehistorical authenticity and 1950s RCA construction\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, accompanied by documented electrical characteristics. The different conditions of the screen printing and signs of use testify to the history of these specimens, without compromising their verified functionality. A \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003ecarefully selected vintage RCA Radiotron pair\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, interesting for enthusiasts who wish to rediscover original American production through tested tubes ready for new use.\u003c\/span\u003e\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 a consistent balance, fully compatible with 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 perfectly 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 Perfectly 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 One tube in sufficient condition, with the screen printing almost completely absent and obvious signs of use, the other in Good condition – Partially eroded lettering, but still legible. Tube body in good condition. See photos for details.\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eManufacturing codes:\u003c\/strong\u003e \u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e4-0? 274 → RMA\/EIA Open Date Code → manufactured in the ??th week of 1954 - 274 → Radio Corporation of America, Camden, N. J.\u003c\/p\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e4-09 → RMA\/EIA Open Date Code → manufactured in the 9th week of 1954 - by Radio Corporation of America, Camden, N. J.\u003c\/p\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":59696801153372,"sku":"03907","price":119.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/2_02857fec-1e17-4db6-a1b7-90e93c6a70a2.jpg?v=1793359542","url":"https:\/\/vacuumtubestreasures.com\/en-lu\/products\/6sn7gt-rca-radiotron-matched-pair-silver-logo-black-plates-d-getter-amplitrex-tested-low-noise-mic-tubes","provider":"Vacuum Tubes Treasures","version":"1.0","type":"link"}