{"product_id":"b749-genalex-gec-amplitrex-tested-original-uk-stable-low-microphonics","title":"Genalex (GEC) B749 12AU7 \/ ECC82 - Original UK - Amplitrex Tested - Rare Vintage","description":"\u003cp style=\"text-align: left;\"\u003e\u003cstrong\u003eGenalex (GEC) B749 12AU7 \/ ECC82 - Original UK - Amplitrex Tested - Rare Vintage\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp style=\"text-align: left;\"\u003e \u003cstrong\u003eOriginal UK Genalex \/ GEC B749 example, nowadays difficult to find on the market, offered as an authentic vintage valve, professionally tested and fully functional.\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch3 style=\"text-align: left;\"\u003e\n\n \u003cstrong\u003eDescription:\u003c\/strong\u003e\u003cstrong\u003e\u003c\/strong\u003e\n\n\u003c\/h3\u003e\n\u003cp class=\"p1\"\u003e This \u003cspan class=\"s1\"\u003e\u003cb\u003eGenalex (GEC) B749 12AU7 \/ ECC82\u003c\/b\u003e\u003c\/span\u003e represents one of the rarest and most sought-after versions of the original British production.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e The \u003cspan class=\"s1\"\u003e\u003cb\u003eB749\u003c\/b\u003e\u003c\/span\u003e designation identifies a special Genalex\/GEC selection designed to meet high quality standards. Original UK valves of this series are difficult to find today, especially in structurally sound and defect-free condition.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e \u003cspan class=\"s1\"\u003e\u003cb\u003eOriginal UK\u003c\/b\u003e\u003c\/span\u003e copy, not a modern reissue.\u003c\/p\u003e\n\u003ch3 style=\"text-align: left;\"\u003e \u003cstrong\u003eSound Characteristics\u003c\/strong\u003e\n\u003c\/h3\u003e\n\u003cp\u003e \u003cstrong\u003eBass:\u003c\/strong\u003e Controlled and compact, with good definition and no artificial emphasis.\u003c\/p\u003e\n\u003cp\u003e \u003cstrong\u003eMedium:\u003c\/strong\u003e Natural and easy to read, with a balanced and consistent timbre.\u003c\/p\u003e\n\u003cp\u003e \u003cstrong\u003eHighs:\u003c\/strong\u003e Clean and composed, with good extension and no harshness.\u003c\/p\u003e\n\u003cp\u003e \u003cstrong\u003eDynamics:\u003c\/strong\u003e Linear and predictable, with stable behavior.\u003c\/p\u003e\n\u003cp\u003e \u003cstrong\u003eSoundstage:\u003c\/strong\u003e Tidy and well-focused, with correct separation of the sound planes.\u003c\/p\u003e\n\u003ch3 style=\"text-align: left;\"\u003e \u003cb\u003e🎧 Use in Hi-Fi Amplifiers\u003c\/b\u003e\n\u003c\/h3\u003e\n\u003cp class=\"p1\"\u003e Suitable for:\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli class=\"p1\"\u003e Line preamplifiers\u003c\/li\u003e\n\n\u003cli class=\"p1\"\u003e Driver stage\u003c\/li\u003e\n\n\u003cli class=\"p1\"\u003e Instrument amplifiers\u003c\/li\u003e\n\n\u003cli class=\"p1\"\u003e Applications where historical character and originality are sought UK\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003ch3 style=\"text-align: left;\"\u003e \u003cstrong\u003e🎯 Note for audiophiles and technicians\u003c\/strong\u003e\n\u003c\/h3\u003e\n\u003cul\u003e\u003c\/ul\u003e\n\u003cp class=\"p1\"\u003e This is not a B749 reissue, but an \u003cspan class=\"s1\"\u003e\u003cb\u003eOriginal UK Genalex \/ GEC\u003c\/b\u003e\u003c\/span\u003e example.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e Offered as a rare and historically significant tube, tested and fully functional, with low microphonics and stable behavior.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3 style=\"text-align: left;\"\u003e \u003cstrong\u003eTest Results:\u003c\/strong\u003e\n\u003c\/h3\u003e\n\u003cp style=\"text-align: left;\"\u003e \u003cstrong\u003eValve tested on AMPLITREX AT-1000 Tube Tester:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul style=\"text-align: left;\"\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eTest Conditions:\u003c\/strong\u003e Va = 250V, Vg = -8.5V\u003c\/li\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eAverage 100%:\u003c\/strong\u003e Gm = 2200 ; Ia = 10.5 mA\u003c\/li\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eTest Result:\u003c\/strong\u003e\n\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp style=\"text-align: left;\"\u003e \u003cstrong\u003eValve:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul style=\"text-align: left;\"\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eSection 1:\u003c\/strong\u003e Gm = 1200 ; Ia = 8.8 mA\u003c\/li\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eSection 2:\u003c\/strong\u003e Gm = 1100 ; Ia = 6.2 mA\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e The Gm measurements are lower than the nominal reference value; however, the valve shows stable operation, absence of abnormal noises and consistent behavior in dynamic tests.\u003cbr\u003e\u003c\/p\u003e\n\u003cp style=\"text-align: left;\"\u003e \u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cul style=\"text-align: left;\"\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eMicrophonics:\u003c\/strong\u003e Low. Suitable for use in hi-fi and guitar amplifiers, including sensitive stages.\u003c\/li\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eOutput Quality:\u003c\/strong\u003e Stable – Output is regular and consistent with the measurements taken.\u003cbr\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eShort circuits and GAS:\u003c\/strong\u003e Absent.\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3 style=\"text-align: left;\"\u003e \u003cstrong\u003eConditions:\u003c\/strong\u003e\n\u003c\/h3\u003e\n\u003cul style=\"text-align: left;\"\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eCondition:\u003c\/strong\u003e Vintage tubes - Tested and in perfect working order. Shipped in our custom box for optimal protection.\u003c\/li\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eFunctionality:\u003c\/strong\u003e Fully functional.\u003c\/li\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eCosmetic condition:\u003c\/strong\u003e Good – Lettering partially eroded, but still legible. Valve body in good condition. See photos for details.\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp style=\"text-align: left;\"\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":"GEC","offers":[{"title":"Default Title","offer_id":56811567382876,"sku":"03442-ONSPEC","price":1310.0,"currency_code":"ILS","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/2_ae86e117-ae56-4b19-a209-4548aa44f9a9.jpg?v=1771931487","url":"https:\/\/vacuumtubestreasures.com\/en-il\/products\/b749-genalex-gec-amplitrex-tested-original-uk-stable-low-microphonics","provider":"Vacuum Tubes Treasures","version":"1.0","type":"link"}