{"product_id":"jhs-6x4w-ez90-nos-nib-sylvania-tested-tube-black-plates-square-getter-made-in-usa-59","title":"JHS 6X4W EZ90 NOS NIB SYLVANIA Tested Tube Black Plates Square Getter Made in USA '59","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003eJHS 6X4W EZ90 NOS NIB SYLVANIA Tested Tube Black Plates Square Getter Made in USA '59\u003c\/strong\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-start=\"424\" data-end=\"874\"\u003eThe Sylvania JHS 6X4W (EZ90), manufactured in the USA in 1959 and supplied in \u003cstrong data-start=\"513\" data-end=\"524\"\u003eNOS NIB\u003c\/strong\u003e (New Old Stock – New in Box) condition, represent one of the most prestigious military versions of this double half-wave rectifier.\u003cbr data-start=\"666\" data-end=\"669\"\u003eThe acronym \u003cstrong data-start=\"678\" data-end=\"716\"\u003eJHS (Joint Army-Navy\/Signal Corps)\u003c\/strong\u003e identifies American military production, selected to withstand critical applications where maximum reliability and long life were required.\u003c\/p\u003e\n\u003cp data-start=\"876\" data-end=\"1316\"\u003eUnlike the common 6X4, the \u003cstrong data-start=\"916\" data-end=\"923\"\u003e“W”\u003c\/strong\u003e acronym indicates the \u003cstrong data-start=\"943\" data-end=\"957\"\u003eruggedized\u003c\/strong\u003e version, that is, reinforced to resist shocks, vibrations and severe operating conditions. \u003cbr data-start=\"1040\" data-end=\"1043\"\u003eAs reported in the datasheet, the 6X4W was designed to operate in half-wave or full-wave rectification, even in combination with vibratory inverters, and was specifically tested for industrial and military applications subjected to intense mechanical shock and vibration.\u003c\/p\u003e\n\u003cp data-start=\"1318\" data-end=\"1570\"\u003eThis valve, equipped with \u003cstrong data-start=\"1351\" data-end=\"1383\"\u003eblack plates and square getter\u003c\/strong\u003e , combines construction robustness, operational silence and a unique historical charm, making it ideal for high-quality hi-fi and philological restorations of vintage military or civilian equipment.\u003c\/p\u003e\n\u003ch3 data-start=\"1572\" data-end=\"1626\"\u003eTimbral characteristics and sound behavior\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli data-start=\"1629\" data-end=\"1728\"\u003e\u003cstrong data-start=\"1629\" data-end=\"1638\"\u003eBass\u003c\/strong\u003e : Compact and tight, with firm control that adds precision to the low register.\u003c\/li\u003e\n\u003cli data-start=\"1731\" data-end=\"1881\"\u003e\u003cstrong data-start=\"1731\" data-end=\"1739\"\u003eMids\u003c\/strong\u003e : Clear and linear, with a natural sound free of artificial coloration. Voices and acoustic instruments emerge with great realism.\u003c\/li\u003e\n\u003cli data-start=\"1884\" data-end=\"1991\"\u003e\u003cstrong data-start=\"1884\" data-end=\"1892\"\u003eHighs\u003c\/strong\u003e : defined and fluid, never harsh, with an elegant detail that gives brilliance without tiring.\u003c\/li\u003e\n\u003cli data-start=\"1994\" data-end=\"2102\"\u003e\u003cstrong data-start=\"1994\" data-end=\"2006\"\u003eDynamics\u003c\/strong\u003e : prompt and consistent, capable of ensuring stable power even in complex passages.\u003c\/li\u003e\n\u003cli data-start=\"2105\" data-end=\"2220\"\u003e\u003cstrong data-start=\"2105\" data-end=\"2119\"\u003eSoundstage\u003c\/strong\u003e : Stable and well-focused soundstage, with noise reduction and deeper black background.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"2222\" data-end=\"2438\"\u003e🎧 \u003cstrong data-start=\"2225\" data-end=\"2255\"\u003eUse in Hi-Fi amplifiers\u003c\/strong\u003e\u003cbr data-start=\"2255\" data-end=\"2258\"\u003ePerfect for hi-fi equipment and tube tuners using EZ90\/6X4 rectifiers, these Sylvania JHS ensure clean power, reliability and long operating life.\u003c\/p\u003e\n\u003cp data-start=\"2440\" data-end=\"2647\"\u003e🎸 \u003cstrong data-start=\"2443\" data-end=\"2490\"\u003eUse in musical instrument amplifiers\u003c\/strong\u003e\u003cbr data-start=\"2490\" data-end=\"2493\"\u003eIn vintage musical instrument amplifiers, they guarantee a warm and quiet sound, with stable harmonic response and free from unwanted noise.\u003c\/p\u003e\n\u003cp data-start=\"2649\" data-end=\"3269\"\u003e🎯 \u003cstrong data-start=\"2652\" data-end=\"2684\"\u003eNote for audiophiles and technicians\u003c\/strong\u003e\u003cbr data-start=\"2684\" data-end=\"2687\"\u003eThe \u003cstrong data-start=\"2697\" data-end=\"2784\"\u003eJHS 6X4W (EZ90) Sylvania – Black Plates – Square Getter – NOS NIB – Made in USA '59\u003c\/strong\u003e represents one of the rarest and most prestigious versions of this rectifier.\u003cbr data-start=\"2864\" data-end=\"2867\"\u003eThanks to the reinforced “W” construction, it is particularly suitable not only for philological restorations, but also for those seeking maximum operational reliability in hi-fi systems and musical instruments.\u003cbr data-start=\"3059\" data-end=\"3062\"\u003eAn ideal choice for collectors, restorers and enthusiasts who wish to combine impeccable functionality, historical value and construction authenticity typical of 1950s American military production.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cspan\u003eTubes tested on \u003cstrong\u003eFunke W19\u003c\/strong\u003e Tube tester:\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003e\u003cstrong\u003eVoltage Test:\u003c\/strong\u003e\u003cmeta charset=\"utf-8\"\u003e Va = 60V, Vf = 6.3V\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003eAverage 100% Ia = 42 mA\u003c\/span\u003e\u003cbr\u003e\u003cstrong\u003eTest Result: VERY STRONG\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003ePlate current\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eValve:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eSection 1:\u003c\/strong\u003e Ia = 45 mA\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eSection 2:\u003c\/strong\u003e Ia = 45 mA\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cspan\u003ePlate current:\u003c\/span\u003e\u003cstrong\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eAdditional Tests\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e Standard. Tested and approved for use in hi-fi and guitar amplifiers.\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eOutput Quality:\u003c\/strong\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cspan\u003eExcellent – Very strong and stable output, no fluctuations.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eShort circuits and GAS:\u003c\/strong\u003e Absent.\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\u003cstrong\u003eConditions:\u003cspan\u003e \u003c\/span\u003e\u003c\/strong\u003eNOS - NIB - New Old Stock, New In Box - Tested and working - Supplied in original box.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eFunctionality:\u003c\/strong\u003e Fully functional.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eCosmetic condition:\u003c\/strong\u003e \u003cspan\u003eGood – Lettering partially eroded, but still legible. Valve body in good condition. See photos for details.\u003c\/span\u003e\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eManufacturing Code:\u003cspan\u003e \u003c\/span\u003e\u003c\/strong\u003e952 - Manufactured in the 52nd week of 1959\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 durability\" rel=\"noopener\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"SYLVANIA","offers":[{"title":"Default Title","offer_id":55483021853020,"sku":"03112","price":29.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_73336812-4e62-46d1-bb44-335c92da2216.jpg?v=1757948638","url":"https:\/\/vacuumtubestreasures.com\/en-gb\/products\/jhs-6x4w-ez90-nos-nib-sylvania-tested-tube-black-plates-square-getter-made-in-usa-59","provider":"Vacuum Tubes Treasures","version":"1.0","type":"link"}