{"product_id":"6sn7-gta-nos-sylvania-black-plates-tall-glass-matched-quad-codes-made-in-usa-46-copia","title":"6SN7GTA NOS Sylvania – Black Plates Tall Glass Matched Quad Tubes USA '56","description":"\u003cp\u003e\u003cstrong\u003e6SN7 GTA NOS SYLVANIA Black Plates TALL GLASS Matched Quad \u0026amp; Codes Made in USA '56\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e \u003cstrong\u003eThese tubes, manufactured in the USA in 1956\u003c\/strong\u003e , offer a rich, dynamic sound, particularly appreciated by audiophiles and musicians who use tube amplifiers. With the distinctive \"Black Plates Tall Glass\" construction and distinctive chrome top, these 6SN7 GTAs feature a well-balanced sound signature, combining deep bass with excellent clarity in the mid- and high-frequencies.\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cp\u003e \u003cstrong\u003eLow range\u003c\/strong\u003e : tight and well-controlled, with defined bass that provides a solid and precise sound base without ever being intrusive. Ideal for those seeking robust and balanced sound reproduction.\u003c\/p\u003e\n\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cp\u003e \u003cstrong\u003eMidrange\u003c\/strong\u003e : Rich and natural, with a remarkable presence that enhances vocals and instruments with detail and immersiveness. Midrange frequencies are smooth and transparent, making these tubes ideal for those seeking an expressive and dynamic sound capable of conveying the subtlest nuances of music.\u003c\/p\u003e\n\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cp\u003e \u003cstrong\u003eHigh Frequencies\u003c\/strong\u003e : sweet and crystalline, with a brilliance that never tires the listener. The special construction contributes to crystal clarity, allowing you to capture every detail without losing the overall warmth of the sound.\u003c\/p\u003e\n\n\n\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003ch3\u003e \u003cstrong\u003eTest Results:\u003c\/strong\u003e\n\u003c\/h3\u003e\n\u003cp\u003e Valves 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\n\u003c\/li\u003e\n\n\u003cli\u003e \u003cstrong\u003eTest Result: VERY STRONG\u003c\/strong\u003e\n\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e \u003cstrong\u003eValve 1:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003e Section 1: Gm = 2500 ; Ia = 7.8 mA\u003c\/li\u003e\n\n\u003cli\u003e Section 2: Gm = 2600 ; Ia = 8.0 mA\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e \u003cstrong\u003eValve 2:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003e Section 1: Gm = 2500 ; Ia = 6.6 mA\u003c\/li\u003e\n\n\u003cli\u003e Section 2: Gm = 2600 ; Ia = 7.4 mA\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e \u003cstrong\u003eValve 3:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003e Section 1: Gm = 2500 ; Ia = 6.8 mA\u003c\/li\u003e\n\n\u003cli\u003e Section 2: Gm = 2600 ; Ia = 7.0 mA\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e \u003cstrong\u003eValve 4:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003e Section 1: Gm = 2500 ; Ia = 6.6 mA\u003c\/li\u003e\n\n\u003cli\u003e Section 2: Gm = 2600 ; Ia = 7.2 mA\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003ch3\u003e \u003cstrong\u003eAdditional tests performed:\u003c\/strong\u003e\n\u003c\/h3\u003e\n\u003cul\u003e\n\n\u003cli\u003e Microphonics Test\u003c\/li\u003e\n\n\u003cli\u003e Emission Quality\u003c\/li\u003e\n\n\u003cli\u003e Short Circuit Test\u003c\/li\u003e\n\n\u003cli\u003e GAS Test\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003ch3\u003e \u003cstrong\u003eConditions:\u003c\/strong\u003e\n\u003c\/h3\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eNOS\u003c\/strong\u003e - in our personalized box\u003c\/li\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eManufacturing code:\u003c\/strong\u003e 722 622 -\u003cmeta charset=\"utf-8\"\u003e Produced week 22 of 1956 by SYLVANIA USA\u003c\/li\u003e\n\n\u003cli style=\"font-weight: bold;\"\u003e \u003cstrong\u003eSelect\u003cmeta charset=\"utf-8\"\u003e from the producer for Low Noise \u0026amp; Microphonics\u003c\/strong\u003e\n\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e \u003cstrong\u003e\u003cmeta charset=\"utf-8\"\u003e\n\u003ca rel=\"noopener\" title=\"Why our tubes are different – ​​the VTT protocol that improves sound, reliability and durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003eFind out why our valves are different →\u003c\/a\u003e\u003c\/strong\u003e\u003c\/p\u003e","brand":"SYLVANIA","offers":[{"title":"Default Title","offer_id":53426434408796,"sku":"02555","price":349.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/2_f550c8cc-8e5c-42f7-88f7-add3bc69666f.jpg?v=1731344215","url":"https:\/\/vacuumtubestreasures.com\/en-hr\/products\/6sn7-gta-nos-sylvania-black-plates-tall-glass-matched-quad-codes-made-in-usa-46-copia","provider":"Vacuum Tubes Treasures","version":"1.0","type":"link"}