{"product_id":"ecc88-6dj8-hp-by-amperex-heerlen-factory-tested-tube-made-in-holland-68","title":"ECC88 6DJ8 HP by AMPEREX Heerlen Factory Halo Getter Tested Tube Made In Holland '68","description":"\u003cp\u003e\u003cstrong\u003eECC88 6DJ8 HP by AMPEREX Heerlen Factory \u003cmeta charset=\"utf-8\"\u003eHalo Getter Tested Tube Made In Holland '68\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-end=\"745\" data-start=\"316\"\u003eThis \u003cstrong data-end=\"339\" data-start=\"323\"\u003eECC88 (6DJ8)\u003c\/strong\u003e branded \u003cstrong data-end=\"374\" data-start=\"350\"\u003eHP (Hewlett-Packard)\u003c\/strong\u003e and produced by \u003cstrong data-end=\"400\" data-start=\"389\"\u003eAmperex\u003c\/strong\u003e in the historic plant in \u003cstrong data-end=\"450\" data-start=\"431\"\u003eHeerlen, Holland\u003c\/strong\u003e , in 1968, represents one of the most reliable and linear versions of the European ECC88 family.\u003cbr data-end=\"550\" data-start=\"547\"\u003e\u003cstrong data-end=\"579\" data-start=\"573\"\u003eHP-\u003c\/strong\u003e branded supplies were reserved for measurement instrumentation and precision laboratories, where electrical stability, low noise, and consistency over time were essential requirements.\u003c\/p\u003e\n\u003cp data-end=\"1074\" data-start=\"747\"\u003eThe construction with \u003cstrong data-end=\"781\" data-start=\"766\"\u003egray plates\u003c\/strong\u003e and \u003cstrong data-end=\"798\" data-start=\"784\"\u003eO-getters\u003c\/strong\u003e is typical of the Amperex Heerlen production of the late 60s, known for its tonal balance and dynamic coherence.\u003cbr data-end=\"916\" data-start=\"913\"\u003eThis specimen, tested on \u003cstrong data-end=\"966\" data-start=\"945\"\u003eAmplitrex AT-1000\u003c\/strong\u003e , showed \u003cstrong data-end=\"1005\" data-start=\"990\"\u003eVERY STRONG\u003c\/strong\u003e results, confirming the high output and excellent internal balance.\u003c\/p\u003e\n\u003ch3 data-end=\"1111\" data-start=\"1081\"\u003eSound Characteristics\u003c\/h3\u003e\n\u003cp data-end=\"1647\" data-start=\"1112\"\u003e\u003cstrong data-end=\"1122\" data-start=\"1112\"\u003eBass:\u003c\/strong\u003e Fast, well controlled, with excellent articulation and no swell.\u003cbr data-end=\"1198\" data-start=\"1195\"\u003e\u003cstrong data-end=\"1207\" data-start=\"1198\"\u003eMids:\u003c\/strong\u003e Clear and linear, with a natural timbre that realistically reproduces vocals and acoustic instruments.\u003cbr data-end=\"1316\" data-start=\"1313\"\u003e\u003cstrong data-end=\"1325\" data-start=\"1316\"\u003eHighs:\u003c\/strong\u003e Extended and clean, with fine detail and perfectly neutral balance. \u003cbr data-end=\"1407\" data-start=\"1404\"\u003e\u003cstrong data-end=\"1420\" data-start=\"1407\"\u003eDynamics:\u003c\/strong\u003e fluid and proportionate; the response is immediate but never aggressive, with great naturalness in microcontrasts.\u003cbr data-end=\"1533\" data-start=\"1530\"\u003e\u003cstrong data-end=\"1548\" data-start=\"1533\"\u003eSoundstage:\u003c\/strong\u003e wide and coherent, with precise depth and focus, typical of the Dutch Amperex school.\u003c\/p\u003e\n\u003ch3 data-end=\"1689\" data-start=\"1654\"\u003e🎧 Use in Hi-Fi Amplifiers\u003c\/h3\u003e\n\u003cp data-end=\"2003\" data-start=\"1690\"\u003eIdeal for \u003cstrong data-end=\"1736\" data-start=\"1701\"\u003ehigh-end preamplifiers\u003c\/strong\u003e , \u003cstrong data-end=\"1755\" data-start=\"1738\"\u003etube DACs\u003c\/strong\u003e , \u003cstrong data-end=\"1772\" data-start=\"1757\"\u003ephono stages\u003c\/strong\u003e and \u003cstrong data-end=\"1799\" data-start=\"1775\"\u003ehybrid amplifiers\u003c\/strong\u003e , where transparency, stability and low noise are required.\u003cbr data-end=\"1861\" data-start=\"1858\"\u003eThe HP selection ensures silent, linear and constant operation over time, perfect for \u003cstrong data-end=\"1976\" data-start=\"1966\"\u003eHi-End\u003c\/strong\u003e systems and \u003cstrong data-end=\"2000\" data-start=\"1979\"\u003estudio monitors\u003c\/strong\u003e .\u003c\/p\u003e\n\u003ch3 data-end=\"2048\" data-start=\"2010\"\u003e🎸 Use in Music Amplifiers\u003c\/h3\u003e\n\u003cp data-end=\"2334\" data-start=\"2049\"\u003eAlso appreciated in \u003cstrong data-end=\"2125\" data-start=\"2069\"\u003epreamplifiers for tube instruments and microphones\u003c\/strong\u003e , where it guarantees a clean harmonic output, with natural dynamics and the absence of microphonics.\u003cbr data-end=\"2221\" data-start=\"2218\"\u003eExcellent in \u003cstrong data-end=\"2256\" data-start=\"2244\"\u003eboutique\u003c\/strong\u003e projects or \u003cstrong data-end=\"2291\" data-start=\"2275\"\u003estudio-grade\u003c\/strong\u003e applications that prioritize tonal accuracy.\u003c\/p\u003e\n\u003ch3 data-end=\"2378\" data-start=\"2341\"\u003e🎯 Note for Audiophiles and Technicians\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli data-end=\"2429\" data-start=\"2381\"\u003e\u003cstrong data-end=\"2427\" data-start=\"2381\"\u003eAmperex Heerlen production – Holland (1968)\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli data-end=\"2530\" data-start=\"2432\"\u003e\u003cstrong data-end=\"2467\" data-start=\"2432\"\u003eHewlett-Packard (HP) Supply:\u003c\/strong\u003e Industrial Selection for Low Noise and Electrical Stability\u003c\/li\u003e\n\u003cli data-end=\"2603\" data-start=\"2533\"\u003e\u003cstrong data-end=\"2549\" data-start=\"2533\"\u003eConstruction:\u003c\/strong\u003e gray plates, O-getters, standard ECC88 pinout\u003c\/li\u003e\n\u003cli data-end=\"2755\" data-start=\"2671\"\u003ePerfect for \u003cstrong data-end=\"2753\" data-start=\"2684\"\u003eHi-Fi, measuring instruments, DACs and reference preamplifiers\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\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\u003eVa = 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\u003e\u003cstrong\u003eValve\u003c\/strong\u003e :\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eSection 1\u003c\/strong\u003e : Gm = 11.9; Ia = 13.0 mA\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eSection 2\u003c\/strong\u003e : Gm = 12.0; Ia = 13.5 mA\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cdiv\u003e\u003cstrong\u003e\u003c\/strong\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/div\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e Low. Tested and approved for use in hi-fi, phono stages, and guitar amplifiers, including V1.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eOutput Quality:\u003c\/strong\u003e Excellent – Very strong and stable output, no fluctuations.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eShort circuits and GAS:\u003c\/strong\u003e Absent.\u003c\/span\u003e\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\u003eCondition:\u003c\/strong\u003e Vintage tubes - Tested and in perfect working order. Shipped in our custom box for optimal protection.\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\u003eAesthetic condition:\u003c\/strong\u003e \u003cspan\u003eVery good – Clearly legible writing with minor signs of wear, no obvious defects. See photos for details.\u003c\/span\u003e\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eManufacturing Code:\u003c\/strong\u003e GA0 ⊿8D3 →\u003cmeta charset=\"utf-8\"\u003e GAx indicates an ECC88 with the sequential progression of x -\u003cmeta charset=\"utf-8\"\u003e ⊿8D3 ⊿ → Heerlen (Netherlands), 8 (four digits) → 1968 - D → April - 3 → 3rd week of the month\u003c\/li\u003e\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 durability\" href=\"https:\/\/vacuumtubestreasures.com\/blogs\/notizie\/perche-le-nostre-valvole-sono-diverse\" target=\"_blank\"\u003e\u003cstrong\u003eFind out why our valves are different →\u003c\/strong\u003e\u003c\/a\u003e\u003cmeta charset=\"utf-8\"\u003e\u003c\/p\u003e","brand":"AMPEREX","offers":[{"title":"Default Title","offer_id":55831823417692,"sku":"03233","price":510.0,"currency_code":"HKD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_a5df2c2e-249a-4345-80f5-9ead4c1722e2.jpg?v=1761666567","url":"https:\/\/vacuumtubestreasures.com\/en-hk\/products\/ecc88-6dj8-hp-by-amperex-heerlen-factory-tested-tube-made-in-holland-68","provider":"Vacuum Tubes Treasures","version":"1.0","type":"link"}