{"product_id":"cv4004-mullard","title":"CV4004 Mullard","description":"\u003cdiv class=\"n6owBd awi2gc\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-hveid=\"CAIIAAgACAoQAA\" data-complete=\"true\"\u003e\n\u003cspan data-subtree=\"aimfl,mfl\"\u003eThe \u003c\/span\u003e\u003cstrong class=\"rQesXe MPyX\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-complete=\"true\"\u003eMullard CV4004\u003c!--TgQPHd|||[]--\u003e\u003c\/strong\u003e is a \u003cmark class=\"b6AQX\" data-wiz-attrbind=\"class=uzW4H_r\/cFwyDc\" data-sfc-root=\"c\" data-ved=\"2ahUKEwjvraHb5NmXAxUCTkEAHRu5EpAQuJAPegoIAggACAAIChAB\" data-complete=\"true\"\u003ehigh-gain, low-noise miniature twin-triode vacuum tube\u003c!--TgQPHd|||[[[null,null,null,null,null,null,null,null,null,null,null,null,[247864,null,0]]]]--\u003e\u003c\/mark\u003e that serves as a military-specification variant of the classic \u003cstrong class=\"rQesXe MPyX\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-complete=\"true\"\u003e12AX7 \/ ECC83\u003c!--TgQPHd|||[]--\u003e\u003c\/strong\u003e (also known as the M8137).\u003cspan\u003e [\u003ca href=\"https:\/\/www.youtube.com\/watch?v=nKvBX6rGpdo\u0026amp;t=10\"\u003e1\u003c\/a\u003e, \u003ca href=\"https:\/\/shop.ehx.com\/catalog\/tubes-specs\/CV4004-12AX7%20Mullard.pdf\"\u003e2\u003c\/a\u003e, \u003ca href=\"https:\/\/www.facebook.com\/py6cj\/posts\/the-mullard-cv4004-m8137-is-a-legendary-military-spec-high-mu-twin-triode-vacuum\/1124537100103189\/\"\u003e3\u003c\/a\u003e]\u003c\/span\u003e\u003c!--TgQPHd|||[]--\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"yhAwj\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-complete=\"true\" data-sfc-inited=\"2\"\u003e\u003c!--TgQPHd|||[]--\u003e\u003c\/div\u003e\n\u003cdiv class=\"ZLzG0d ncoeY E8xBUb\" role=\"heading\" aria-level=\"3\" data-animation-nesting=\"\" data-sfc-cp=\"\" data-wiz-attrbind=\"aria-level=uzW4H_12\/fLk2Md\" data-sfc-root=\"c\" data-complete=\"true\"\u003eKey Characteristics \u0026amp; Origins\u003c!--TgQPHd|||[[2,[null,null,null,null,null,null,null,null,null,null,null,null,[351768,null,0]],[],null,1]]--\u003e\n\u003c\/div\u003e\n\u003cdiv data-bfc=\"\" class=\"\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-ved=\"2ahUKEwjvraHb5NmXAxUCTkEAHRu5EpAQi4wTegoIAggACAAIGhAB\" data-hveid=\"CAIIAAgACBoQAQ\" data-complete=\"true\"\u003e\n\u003cspan class=\"iNqyIf\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-complete=\"true\"\u003e\u003cstrong class=\"rQesXe MPyX\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-complete=\"true\"\u003eOriginal vs. Reissue:\u003c!--TgQPHd|||[]--\u003e\u003c\/strong\u003e\u003c!--TgQPHd|||[]--\u003e\u003c\/span\u003e\n\u003cul class=\"XSq4R KI3fJ\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-hveid=\"CAIIAAgACBoQAw\" data-complete=\"true\"\u003e\n\u003cli class=\"Z1qcYe\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-hveid=\"CAIIAAgACBoQBA\" data-complete=\"true\"\u003e\n\u003cspan class=\"iNqyIf\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-complete=\"true\"\u003e\u003cstrong class=\"rQesXe MPyX\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-complete=\"true\"\u003eOriginal (NOS - New Old Stock):\u003c!--TgQPHd|||[]--\u003e\u003c\/strong\u003e Originally manufactured in Great Britain for the English military, vintage Mullard CV4004 \/ M8137 tubes feature rugged construction, box-shaped plates, and a warm, dynamic, low-microphonic sound. Genuine NOS units command high collector and audiophile prices (frequently $250+ when available).\u003c!--TgQPHd|||[]--\u003e\u003c\/span\u003e\u003c!--TgQPHd|||[]--\u003e\n\u003c\/li\u003e\n\u003cli class=\"Z1qcYe\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-hveid=\"CAIIAAgACBoQBQ\" data-complete=\"true\"\u003e\n\u003cspan class=\"iNqyIf\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-complete=\"true\"\u003e\u003cstrong class=\"rQesXe MPyX\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-complete=\"true\"\u003eNew Production (Reissue):\u003c!--TgQPHd|||[]--\u003e\u003c\/strong\u003e Current-production Mullard CV4004 \/ 12AX7 tubes are manufactured in Russia by the New Sensor Corporation at the Saratov (Reflektor) factory. They are built with a short-plate structure designed to minimize physical vibration and microphonics in combo and high-gain guitar amplifiers.\u003c!--TgQPHd|||[]--\u003e\u003c\/span\u003e\u003cspan\u003e [\u003ca href=\"https:\/\/upscaleaudio.com\/products\/mullard-new-production-cv4004-12ax7\"\u003e1\u003c\/a\u003e, \u003ca href=\"https:\/\/www.tubedepot.com\/products\/mullard-cv4004-12ax7\"\u003e2\u003c\/a\u003e, \u003ca href=\"https:\/\/www.thetubestore.com\/mullard-cv4004-12ax7\"\u003e3\u003c\/a\u003e, \u003ca href=\"https:\/\/www.tubedepot.com\/products\/mullard-cv4004-12ax7-new-production-preamp-vacuum-tube\"\u003e4\u003c\/a\u003e, \u003ca href=\"https:\/\/www.facebook.com\/py6cj\/posts\/the-mullard-cv4004-m8137-is-a-legendary-military-spec-high-mu-twin-triode-vacuum\/1124537100103189\/\"\u003e5\u003c\/a\u003e]\u003c\/span\u003e\u003c!--TgQPHd|||[]--\u003e\n\u003c\/li\u003e\n\u003c!--TgQPHd|||[]--\u003e\n\u003c\/ul\u003e\n\u003c!--TgQPHd|||[]--\u003e\u003c!--TgQPHd|||[]--\u003e\n\u003c\/div\u003e\n\u003cdiv data-bfc=\"\" class=\"\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-ved=\"2ahUKEwjvraHb5NmXAxUCTkEAHRu5EpAQi4wTegoIAggACAAIGhAK\" data-hveid=\"CAIIAAgACBoQCg\" data-complete=\"true\"\u003e\n\u003cspan class=\"iNqyIf\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-complete=\"true\"\u003e\u003cstrong class=\"rQesXe MPyX\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-complete=\"true\"\u003eTone \u0026amp; Performance:\u003c!--TgQPHd|||[]--\u003e\u003c\/strong\u003e\u003c!--TgQPHd|||[]--\u003e\u003c\/span\u003e\n\u003cul class=\"XSq4R KI3fJ\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-hveid=\"CAIIAAgACBoQDA\" data-complete=\"true\"\u003e\n\u003cli class=\"Z1qcYe\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-hveid=\"CAIIAAgACBoQDQ\" data-complete=\"true\"\u003e\n\u003cspan class=\"iNqyIf\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-complete=\"true\"\u003eKnown for a smooth midrange, strong bass response, and relaxed top end.\u003c!--TgQPHd|||[]--\u003e\u003c\/span\u003e\u003c!--TgQPHd|||[]--\u003e\n\u003c\/li\u003e\n\u003cli class=\"Z1qcYe\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-hveid=\"CAIIAAgACBoQDg\" data-complete=\"true\"\u003e\u003cspan class=\"iNqyIf\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-complete=\"true\"\u003eWidely used and recommended for high-gain pre-amplifier stages (such as Marshall-style guitar amps) and sensitive phono stages where mechanical rattling or hiss can be an issue.\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e","brand":"Mullard","offers":[{"title":"Default Title","offer_id":67887541256271,"sku":null,"price":450.0,"currency_code":"ZAR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0669\/4354\/9519\/files\/images_2c94993b-6e57-4bf9-a817-5716a725da3b.jpg?v=1793090079","url":"https:\/\/theoldstockroom.com\/products\/cv4004-mullard","provider":"The Old Stockroom","version":"1.0","type":"link"}