{"product_id":"ecc88-6dj8-sylvania-amplitrex-matched-pair-tubes-made-in-usa","title":"ECC88 \/ 6DJ8 SYLVANIA AMPLITREX Matched Pair Tubes Made in USA","description":"\u003ch3\u003e\u003cstrong\u003eECC88 \/ 6DJ8 SYLVANIA Halo Getter Tested Tubes Made in USA '60s\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eAMPLITREX Matched Pair – Low Noise \u0026amp; Microphonics – Vintage American SYLVANIA Production\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eTested on \u003cstrong\u003eAMPLITREX AT-1000\u003c\/strong\u003e Tube Tester\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eVoltage Test:\u003cspan\u003e \u003c\/span\u003e\u003c\/strong\u003e Va = 90V ; Vg = -1.2V\u003cstrong\u003e\u003cbr\u003eAverage 100%:\u003c\/strong\u003e Gm = 12.5 ; Ia = 15.0 mA\u003cstrong\u003e\u003cbr\u003eTEST RESULT:\u003c\/strong\u003e VERY STRONG\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e\u003cstrong\u003eTube #1:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003eSection 1: Gm = 12.91 ; Ia = 14.9 mA\u003c\/li\u003e\n\n\u003cli\u003eSection 2: Gm = 12.30 ; Ia = 14.7 mA\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp class=\"p1\"\u003e\u003cstrong\u003eTube #2:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003eSection 1: Gm = 12.20 ; Ia = 12.6 mA\u003c\/li\u003e\n\n\u003cli\u003eSection 2: Gm = 12.71 ; Ia = 14.4 mA\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cdiv\u003e\n\n\u003cstrong\u003e\u003c\/strong\u003e\u003cbr\u003e\n\n\u003c\/div\u003e\n\u003cdiv\u003e\n\n\u003cmeta charset=\"utf-8\"\u003e\n\n\u003cdiv\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/div\u003e\n\n\u003cul\u003e\n\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eBurn-in \/ Stability Test:\u003c\/strong\u003e 48h – OK\u003c\/span\u003e\u003c\/li\u003e\n\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e Low. Tested and compliant for use in hi-fi equipment and guitar amplifiers, even in the most sensitive audio stages.\u003c\/span\u003e\u003c\/li\u003e\n\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eBalance:\u003c\/strong\u003e Good. The sections show a consistent balance, fully compatible for use in hi-fi environments and musical amplifiers, in all applications where absolute symmetry between sections is not required.\u003c\/span\u003e\u003c\/li\u003e\n\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eEmission Quality:\u003c\/strong\u003e Excellent – Very strong and stable emission, without fluctuations.\u003c\/span\u003e\u003c\/li\u003e\n\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eShort Circuits and GAS:\u003c\/strong\u003e Absent.\u003c\/span\u003e\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\n\u003c\/div\u003e\n\u003ch3\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-pm-slice=\"1 1 []\"\u003e\u003cspan\u003eA unique pair of \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eAmerican-made ECC88 \/ 6DJ8 Sylvania tubes\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, dating approximately to the \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e1960s\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e and featuring \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eHalo Getter\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e construction. The two units belong to different Sylvania commercial series: one retains the gold \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eGold Brand\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e marking, while the other is from standard production and has completely faded lettering. The internal structure and main construction features are nevertheless consistent.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe presence of one \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eSylvania Gold Brand\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e unit gives the pair additional interest. This designation identified the premium commercial line offered by Sylvania, while the second unit uses standard American production branding. This is therefore not a pair that is aesthetically identical or from the same series, but two tubes selected together based on their actual electrical performance.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eTests performed with the \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eAmplitrex AT-1000\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e indeed highlight a particularly precise match. The first tube has an average transconductance of about \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e12.61 mA\/V\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, while the second reaches about \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e12.46 mA\/V\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e: a difference of just over \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e1%\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e. The average plate currents, equal to \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e14.8 and 13.5 mA\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e respectively, also confirm good overall consistency between the two units.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eIndividual transconductance values are between \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e12.20 and 12.91 mA\/V\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, being very close to or above the nominal reference of \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e12.5 mA\/V\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e. The first tube shows particularly uniform sections; in the second, there is a more evident difference in plate current, while still maintaining stable behavior and being fully suitable for applications where absolute symmetry is not required.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e48-hour burn-in\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e confirmed the stability of the parameters with no fluctuations. The pair features \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003elow microphonics and low noise\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, absence of gas, and no short circuits, making them suitable even for the most sensitive audio stages.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThese tubes are suitable for hi-fi preamplifiers, line stages, buffers, headphone amplifiers, and other circuits compatible with ECC88\/6DJ8, as well as musical instrument amplifiers. The close transconductance matching makes them particularly valuable in stereo equipment where it is important to maintain uniformity between the two channels.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eSonically, Sylvania production is appreciated for an \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eopen, dynamic, and natural\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e presentation, with a transparent midrange, defined and airy high frequencies, and precise, controlled bass. The excellent electrical matching promotes a stable soundstage, good imaging, and consistent response between channels.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eA unique offering for those looking for a \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003evintage American Sylvania pair from the '60s\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, consisting of two units selected to offer very close electrical values: two Halo Getter tubes with strong emission, low microphonics, and stable operation, tested individually and ready for use.\u003c\/span\u003e\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eConditions:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eConditions:\u003c\/strong\u003e Vintage Tubes - Tested and perfectly functional. Supplied in our custom box for optimal protection.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eFunctionality: \u003c\/strong\u003ePerfectly operational.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eCosmetic Condition:\u003c\/strong\u003e\u003cspan\u003e Small difference in manufacturing series between the two units: one unit is part of the Gold Brand production, the other is standard production. The construction and identifying characteristics are consistent, however. One of the two units has completely missing lettering. See photos for details.\u003c\/span\u003e\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eManufacturing Code:\u003c\/strong\u003e Code undecipherable. Production attributable approximately to the '60s based on construction characteristics.\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca rel=\"noopener\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability, and longevity\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eDiscover why our tubes are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003cmeta charset=\"utf-8\"\u003e\u003c\/p\u003e","brand":"SYLVANIA","offers":[{"title":"Default Title","offer_id":59336094351708,"sku":"03862L","price":109.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/9_d29dc25d-914d-486a-b1d6-103f9413f3be.jpg?v=1790937043","url":"https:\/\/vacuumtubestreasures.com\/en-pt\/products\/ecc88-6dj8-sylvania-amplitrex-matched-pair-tubes-made-in-usa","provider":"Vacuum Tubes Treasures","version":"1.0","type":"link"}