{"product_id":"6bq5-el84-ei-for-hammond-gray-plates-halo-getter-matched-tubes-made-in-yugoslavia","title":"6BQ5 \/ EL84 HAMMOND by Ei Gray Plates Halo Getter Matched Quad Tubes Made in YUGOSLAVIA","description":"\u003ch3\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003e6BQ5 \/ EL84 HAMMOND by Ei Gray Plates Halo Getter Matched Quad Tubes Made in Yugoslavia\u003c\/b\u003e\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp class=\"p2\"\u003e\u003cb\u003eAMPLITREX Matched Quad – VERY STRONG – Vintage Ei Production for HAMMOND\u003c\/b\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eGeneral Description\u003c\/b\u003e\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp class=\"p2\"\u003eThis matched quad of \u003cspan class=\"s1\"\u003e\u003cb\u003e6BQ5 \/ EL84 HAMMOND by Ei Niš\u003c\/b\u003e\u003c\/span\u003e, \u003cspan class=\"s1\"\u003e\u003cb\u003eMade in Yugoslavia (today Serbia)\u003c\/b\u003e\u003c\/span\u003e production, represents a particularly interesting selection for enthusiasts of the best classic European EL84s.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eThe tubes were produced by \u003cspan class=\"s1\"\u003e\u003cb\u003eElektronska Industrija (Ei)\u003c\/b\u003e\u003c\/span\u003e and branded for \u003cspan class=\"s1\"\u003e\u003cb\u003eHAMMOND\u003c\/b\u003e\u003c\/span\u003e, a historic manufacturer of professional electronic organs. The construction with \u003cspan class=\"s1\"\u003e\u003cb\u003eGray Plates\u003c\/b\u003e\u003c\/span\u003e and \u003cspan class=\"s1\"\u003e\u003cb\u003eHalo Getter\u003c\/b\u003e\u003c\/span\u003e, combined with the same manufacturing code \u003cspan class=\"s1\"\u003e\u003cb\u003eKM4 ◉7I\u003c\/b\u003e\u003c\/span\u003e, indicates homogeneous production from the same batch.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eA curious and interesting detail is the presence of the “Made in Germany” marking on the tube’s printing. However, the manufacturing code \u003cstrong\u003eKM4 ◉7I\u003c\/strong\u003e unmistakably identifies the actual producer as \u003cstrong\u003eElektronska Industrija (Ei), Yugoslavia\u003c\/strong\u003e, a conclusion further confirmed by the characteristic construction features typical of this highly regarded European production.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eEarly Ei productions are highly valued by enthusiasts because they derive from technologies and manufacturing equipment closely linked to the European tradition of signal and power tubes. Even today, they are considered among the most interesting vintage alternatives to Western-produced EL84s.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eThis quad has been carefully tested using an \u003cspan class=\"s1\"\u003e\u003cb\u003eAMPLITREX AT-1000 Tube Tester\u003c\/b\u003e\u003c\/span\u003e, proving to be \u003cspan class=\"s1\"\u003e\u003cb\u003eVERY STRONG\u003c\/b\u003e\u003c\/span\u003e, with very close values among the four tubes, stable emission, and having \u003cspan class=\"s1\"\u003e\u003cb\u003epassed the 48h Burning Test\u003c\/b\u003e\u003c\/span\u003e.\u003c\/p\u003e\n\u003cp class=\"p3\"\u003eFrom an aesthetic point of view, the tubes are in good overall condition. The HAMMOND markings show normal wear and tear over time, as visible in the photographs, while the internal structures are well preserved.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eSonic Characteristics\u003c\/b\u003e\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp class=\"p2\"\u003eEL84 Ei tubes from this period are appreciated for their ability to combine musicality, dynamic liveliness, and excellent intelligibility of the musical message.\u003c\/p\u003e\n\u003cp\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eBass\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eThe bass range is fast, well-articulated, and controlled. It doesn't aim for artificial emphasis but offers precision and good rhythmic definition.\u003c\/p\u003e\n\u003cp\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eMids\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eThe mids represent one of the strengths of this production. Vocals sound natural and well-focused, while acoustic instruments and guitars maintain a rich and engaging harmonic texture.\u003c\/p\u003e\n\u003cp\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eHighs\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eThe highs are open, detailed, and well-extended, with a lively but generally balanced presentation.\u003c\/p\u003e\n\u003cp\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eDynamics\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eThe dynamic response is prompt and reactive, a quality particularly appreciated in both hi-fi and musical instrument amplifiers.\u003c\/p\u003e\n\u003cp\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eSoundstage\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"p3\"\u003eThe soundstage appears well-organized and stable, with good instrument separation and accurate spatial reconstruction.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003e🎧 Use in Hi-Fi Amplifiers\u003c\/b\u003e\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp class=\"p4\"\u003eThis matched quad is particularly suitable for:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eEL84 \/ 6BQ5 based push-pull amplifiers\u003c\/li\u003e\n\u003cli\u003evintage integrated amplifiers\u003c\/li\u003e\n\u003cli\u003ecompatible Hammond electronics\u003c\/li\u003e\n\u003cli\u003eEuropean and American hi-fi restorations\u003c\/li\u003e\n\u003cli\u003eaudio projects requiring consistent and reliable quads\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"p3\"\u003eThe low microphonics and good matching also make it suitable for particularly demanding applications.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003e🎸 Use in Musical Amplifiers\u003c\/b\u003e\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp class=\"p4\"\u003eEL84 Ei tubes are also highly appreciated by musicians due to characteristics such as:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eexcellent harmonic response\u003c\/li\u003e\n\u003cli\u003elively dynamics\u003c\/li\u003e\n\u003cli\u003edefinition in the mid-high frequencies\u003c\/li\u003e\n\u003cli\u003egood note intelligibility\u003c\/li\u003e\n\u003cli\u003estable performance over time\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"p3\"\u003eThey can represent an interesting choice for guitar amplifiers that use EL84 quads and seek the typical character of vintage European productions.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003e🎯 Note for Audiophiles and Technicians\u003c\/b\u003e\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp class=\"p4\"\u003eThis quad combines numerous elements particularly appreciated by enthusiasts:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eoriginal \u003cspan class=\"s1\"\u003e\u003cb\u003eEi Yugoslavia\u003c\/b\u003e\u003c\/span\u003e production\u003c\/li\u003e\n\u003cli\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eHAMMOND\u003c\/b\u003e\u003c\/span\u003e \u003cspan class=\"s2\"\u003ebrand\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003esame manufacturing code\u003c\/li\u003e\n\u003cli\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eGray Plates\u003c\/b\u003e\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eHalo Getter\u003c\/b\u003e\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eMatched Quad\u003c\/b\u003e\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003e48h Burning Test – OK\u003c\/b\u003e\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eVERY STRONG\u003c\/b\u003e\u003c\/span\u003e \u003cspan class=\"s2\"\u003eperformance\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"p3\"\u003eA particularly interesting vintage selection for those who desire an authentic, consistent, and musically convincing EL84 quad, from one of the most appreciated European productions of the period.\u003c\/p\u003e\n\u003chr\u003e\n\u003cp\u003e\u003cspan\u003eTested on \u003cstrong\u003eAMPLITREX AT-1000\u003c\/strong\u003e Tube tester:\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cstrong\u003eVoltage Test:\u003c\/strong\u003e Va = 250V, Vg2 = 250V, Vg1 = -7.3V\u003cbr\u003e\u003cstrong\u003eAverage 100%\u003c\/strong\u003e Gm = 11.3 ; Ia = 48 mA\u003cbr\u003e\u003cstrong\u003eTEST RESULT: VERY STRONG\u003c\/strong\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eTube 1:\u003c\/strong\u003e Gm 10.90 ; Ia = 47 mA\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eTube 2:\u003c\/strong\u003e Gm 10.90 ; Ia = 47 mA\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eTube 3:\u003c\/strong\u003e Gm 10.87 ; Ia = 43 mA\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eTube 4:\u003c\/strong\u003e Gm 10.55 ; Ia = 42 mA\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eAdditional Tests Performed\u003c\/b\u003e\u003c\/span\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli class=\"p2\"\u003e\u003cb\u003eBurning Test:\u003c\/b\u003e\u003cspan class=\"s2\"\u003e 48h – OK\u003c\/span\u003e\u003c\/li\u003e\n\u003cli class=\"p3\"\u003e\u003cb\u003eMicrophonics:\u003c\/b\u003e Low. Tested and suitable for use in hi-fi and guitar amplifiers.\u003c\/li\u003e\n\u003cli class=\"p3\"\u003e\u003cb\u003eEmission Quality:\u003c\/b\u003e Excellent – very strong and stable emission, without fluctuations.\u003c\/li\u003e\n\u003cli class=\"p2\"\u003e\u003cb\u003eShorts and GAS:\u003c\/b\u003e\u003cspan class=\"s2\"\u003e Absent.\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eCondition\u003c\/b\u003e\u003c\/span\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli class=\"p3\"\u003e\u003cb\u003eCondition:\u003c\/b\u003e Vintage Tubes - Tested and perfectly functional. Supplied in our custom box for optimal protection.\u003c\/li\u003e\n\u003cli class=\"p3\"\u003e\u003cb\u003eFunctionality:\u003c\/b\u003e Perfectly operational.\u003c\/li\u003e\n\u003cli class=\"p3\"\u003e\u003cb\u003eAesthetic Condition:\u003c\/b\u003e Good – Markings partially eroded, but still legible. Tube body in good condition. See photos for details.\u003c\/li\u003e\n\u003cli class=\"p2\"\u003e\u003cb\u003eManufacturing Code: KM4 ◉7I\u003c\/b\u003e\u003cspan class=\"s2\"\u003e → \u003cmeta charset=\"utf-8\"\u003e \u003cb\u003e◉\u003c\/b\u003e indicates the manufacturer, namely \u003cstrong\u003eElektronska industrija\u003c\/strong\u003e\u003c\/span\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003e, YUGOSLAVIA\u003c\/b\u003e\u003c\/span\u003e\u003cspan class=\"s2\"\u003e. \u003cmeta charset=\"utf-8\"\u003e \u003cb\u003e7I\u003c\/b\u003e\u003c\/span\u003e\u003cspan class=\"s2\"\u003e → 7 indicates \u003c\/span\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003e1967\u003c\/b\u003e\u003c\/span\u003e\u003cspan class=\"s2\"\u003e, I indicates the month of September\u003c\/span\u003e\u003cspan class=\"s2\"\u003e.\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cspan class=\"s2\"\u003e\u003cmeta charset=\"utf-8\"\u003e \u003ca rel=\"noopener\" title=\"Why our tubes are different – the VTT protocol that improves sound, reliability and durability\" 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\/span\u003e\u003c\/p\u003e","brand":"Ei","offers":[{"title":"Default Title","offer_id":46684615377244,"sku":"01397","price":119.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/4_8cc41f82-9713-440e-88fd-620f2c7837d0.jpg?v=1781601719","url":"https:\/\/vacuumtubestreasures.com\/en-hr\/products\/6bq5-el84-ei-for-hammond-gray-plates-halo-getter-matched-tubes-made-in-yugoslavia-en","provider":"Vacuum Tubes Treasures","version":"1.0","type":"link"}