{"product_id":"6sl7gt-sylvania-3-hole-black-plates-tall-boys-amplitrex-tested-pair-made-in-usa-50s","title":"6SL7GT SYLVANIA 3-Hole Black Plates Tall Boys AMPLITREX Tested Pair Made in USA '50s","description":"\u003cp\u003e\u003cstrong\u003e6SL7GT SYLVANIA 3-Hole Black Plates Tall Boys AMPLITREX Tested Pair Made in USA '50s\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch3 data-start=\"0\" data-end=\"784\"\u003e\u003cstrong data-start=\"3\" data-end=\"27\"\u003eGeneral Description\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp class=\"p1\"\u003eThis \u003cspan class=\"s1\"\u003e\u003cb\u003epair of 6SL7GT SYLVANIA “Tall Boys”\u003c\/b\u003e\u003c\/span\u003e, produced in the United States in the 1950s, represents one of the most fascinating and recognizable configurations of the great American production.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eThe tubes stand out for their iconic and highly appreciated construction:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"p1\"\u003e\u003cb\u003e3-Hole Black Plates\u003c\/b\u003e\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eTall Boys\u003c\/b\u003e\u003c\/span\u003e structure (tall bottle, typical of early productions)\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cb\u003eDifferent Date Codes but same year of production\u003c\/b\u003e\u003c\/li\u003e\n\u003cli class=\"p1\"\u003eentirely \u003cspan class=\"s1\"\u003e\u003cb\u003eMade in USA\u003c\/b\u003e\u003c\/span\u003e construction\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"p1\"\u003eThis is a \u003cspan class=\"s1\"\u003e\u003cb\u003eselected and tested used pair\u003c\/b\u003e\u003c\/span\u003e, not a random combination, but a conscious choice based on real performance and sonic consistency.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eAlthough not a matched pair, the tubes exhibit a \u003cspan class=\"s1\"\u003e\u003cb\u003econsistent internal balance\u003c\/b\u003e\u003c\/span\u003e, fully compatible with hi-fi and musical use in all applications where strict symmetry is not required.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eTested with \u003cspan class=\"s1\"\u003e\u003cb\u003eAmplitrex AT-1000\u003c\/b\u003e\u003c\/span\u003e, they achieved:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"p1\"\u003e\u003cb\u003eResult: STRONG\u003c\/b\u003e\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cb\u003eInternal VTT Classification: STRONG\u003c\/b\u003e\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cb\u003eLow Noise \u0026amp; Microphonics\u003c\/b\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"p1\"\u003eA proposition that combines \u003cspan class=\"s1\"\u003e\u003cb\u003ehistorical charm, build quality, and authentic musical reproduction\u003c\/b\u003e\u003c\/span\u003e, superior to the average of generic used pairs.\u003c\/p\u003e\n\u003ch3 data-start=\"786\" data-end=\"999\"\u003e\n\u003cstrong data-start=\"788\" data-end=\"814\"\u003eSonic Characteristics\u003c\/strong\u003e\u003cbr data-start=\"814\" data-end=\"817\"\u003e\u003cmeta charset=\"utf-8\"\u003e\n\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eBass\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eSoft and well-articulated, with a natural presence that supports the soundstage without weighing it down.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eMids\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eAbsolute strong point: rich, textural, and three-dimensional. Vocals emerge with great naturalness and engagement.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHighs\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eSweet and well-extended, never aggressive. They offer air and detail while maintaining a consistently musical rendition.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDynamics\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eFluid and progressive, with a natural response that prioritizes musicality and coherence.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eSoundstage\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eWide and airy, with a well-developed stage and credible instrument separation.\u003c\/p\u003e\n\u003ch3 data-end=\"1875\" data-start=\"1819\"\u003e🎧 \u003cstrong data-end=\"1859\" data-start=\"1822\"\u003eUse in Hi-Fi Stereo Amplifiers\u003c\/strong\u003e\n\u003c\/h3\u003e\n\u003cp class=\"p1\"\u003eIdeal for:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"p1\"\u003etube preamplifiers\u003c\/li\u003e\n\u003cli class=\"p1\"\u003einput stages\u003c\/li\u003e\n\u003cli class=\"p1\"\u003ecircuits where musicality and naturalness are required\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"p1\"\u003eThanks to \u003cspan class=\"s1\"\u003e\u003cb\u003elow noise and good internal coherence\u003c\/b\u003e\u003c\/span\u003e, they easily integrate into most hi-fi configurations, offering a natural and engaging sound.\u003c\/p\u003e\n\u003ch3 data-end=\"2229\" data-start=\"2177\"\u003e🎸 \u003cstrong data-end=\"2213\" data-start=\"2180\"\u003eUse in Musical Amplifiers\u003c\/strong\u003e\n\u003c\/h3\u003e\n\u003cp class=\"p1\"\u003eExcellent choice for:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"p1\"\u003evintage instrument amplifiers\u003c\/li\u003e\n\u003cli class=\"p1\"\u003etube preamplifiers\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"p1\"\u003eThey offer:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"p1\"\u003egreat expressiveness in the mids\u003c\/li\u003e\n\u003cli class=\"p1\"\u003emusical dynamic response\u003c\/li\u003e\n\u003cli class=\"p1\"\u003eauthentically \"vintage\" sonic character\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 data-end=\"2611\" data-start=\"2509\"\u003e🎯 \u003cstrong data-end=\"2544\" data-start=\"2512\"\u003eNote for audiophiles and technicians\u003c\/strong\u003e\u003cbr data-end=\"2547\" data-start=\"2544\"\u003e\n\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli class=\"p1\"\u003e\u003cb\u003eSYLVANIA USA – 1950s\u003c\/b\u003e\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cb\u003e3-Hole Black Plates – Tall Boys\u003c\/b\u003e\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cb\u003eDifferent Date Codes (same year)\u003c\/b\u003e\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cb\u003eSelected pair, not matched\u003c\/b\u003e\u003c\/li\u003e\n\u003cli class=\"p1\"\u003e\u003cb\u003eLow Noise \u0026amp; Microphonics\u003c\/b\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"p1\"\u003eA pair that expresses \u003cspan class=\"s1\"\u003e\u003cb\u003eidentity, coherence, and musicality\u003c\/b\u003e\u003c\/span\u003e, designed for those who desire an \u003cspan class=\"s1\"\u003e\u003cb\u003eauthentic American 6SL7\u003c\/b\u003e\u003c\/span\u003e, judiciously selected and capable of offering a credible and satisfying sound experience.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3 data-end=\"3436\" data-start=\"3046\"\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\u003cli\u003e\n\u003cstrong\u003eTest Conditions:\u003c\/strong\u003e \u003cmeta charset=\"utf-8\"\u003eVa = 250V, Vg = -2V\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAverage 100%: \u003c\/strong\u003eGm = 1600 ; Ia = 2.3 mA\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest Result:\u003c\/strong\u003e STRONG\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eTube 1:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eSection 1: Gm = 1500 ; Ia = 2.3 mA\u003c\/li\u003e\n\u003cli\u003eSection 2: Gm = \u003cmeta charset=\"utf-8\"\u003e1400 ; Ia = 2.1 mA\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eTube 2:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eSection 1: Gm = 1200 ; Ia = 2.0 mA\u003c\/li\u003e\n\u003cli\u003eSection 2: Gm = \u003cmeta charset=\"utf-8\"\u003e1300 ; Ia = 2.2 mA\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cdiv\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/div\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e Low. Tested and suitable for hi-fi use, including in phono stages and guitar amplifiers. Also suitable for V1.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan\u003e\u003cstrong\u003eBalance: \u003c\/strong\u003e\u003c\/span\u003eThe sections exhibit a consistent balance, fully compatible with use in hi-fi and musical amplifiers, in all applications where absolute symmetry is not required.\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eEmission Quality:\u003c\/strong\u003e Strong – Strong and regular emission, suitable for any application.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eShorts and GAS:\u003c\/strong\u003e None.\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eConditions:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eConditions:\u003c\/strong\u003e Vintage Tubes - Tested and fully functional - Supplied in Original Box.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFunctionality: \u003c\/strong\u003ePerfectly operational.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAesthetic conditions:\u003c\/strong\u003e\u003cspan\u003e Excellent – Markings are excellently preserved, minimal signs of age. See photos for details.\u003c\/span\u003e\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eManufacturing Code:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e018 → Sylvania Electric Products Inc., Emporium, Pa. - \u003cmeta charset=\"utf-8\"\u003e018 → 0 ( three digits ) → 1950 - 18 → 18th week of the year\u003c\/li\u003e\n\u003cli\u003e\n\u003cmeta charset=\"utf-8\"\u003e022 → Sylvania Electric Products Inc., Emporium, Pa. - \u003cmeta charset=\"utf-8\"\u003e018 → 0 ( three digits ) → 1950 - 22 → 22nd week of the year\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=\"Perché le nostre valvole sono diverse – il protocollo VTT che migliora suono, affidabilità e durata\" rel=\"noopener\" target=\"_blank\"\u003e\u003cstrong\u003eDiscover why our tubes are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"SYLVANIA","offers":[{"title":"Default Title","offer_id":57302117417308,"sku":"03516","price":99.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/3_87bc1dd6-250d-43ec-aff2-ba321c6fcf5e.jpg?v=1775665745","url":"https:\/\/vacuumtubestreasures.com\/en-lv\/products\/6sl7gt-sylvania-3-hole-black-plates-tall-boys-amplitrex-tested-pair-made-in-usa-50s","provider":"Vacuum Tubes Treasures","version":"1.0","type":"link"}