{"product_id":"12ax7-ecc83-nos-philips-heerlen-1964-short-gray-plates-halo-getter-amplitrex-tested","title":"12AX7 \/ ECC83 NOS EVERETT by Philips Heerlen Matched Pair 1964 Short Gray Plates HOLLAND MADE","description":"\u003ch3\u003e\u003cstrong\u003e12AX7 \/ ECC83 NOS EVERETT by Philips, Heerlen plant, Short Gray Plates Halo Getter MADE IN HOLLAND 1964\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eMatched Pair – AMPLITREX Tested – Vintage Holland Production – Low Noise \u0026amp; Microphonics\u003c\/strong\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eTube tested on \u003cstrong\u003eAMPLITREX AT-1000 \u003c\/strong\u003eTube Tester:\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest Conditions:\u003c\/strong\u003e\u003cspan\u003e Va = 250V ; Vg = -2V\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAverage 100%:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eGm = 1600 ; Ia = 1.2 mA\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest Result:\u003c\/strong\u003e VERY STRONG\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eTube 1:\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSection 1:\u003c\/strong\u003e\u003cspan\u003e Gm = 1600 ; Ia = 1.1 mA\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSection 2:\u003c\/strong\u003e\u003cspan\u003e Gm = 1700 ; Ia = \u003cmeta charset=\"utf-8\"\u003e1.2 mA\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eTube 2:\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSection 1:\u003c\/strong\u003e\u003cspan\u003e Gm = 1800 ; Ia = 1.3 mA\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSection 2:\u003c\/strong\u003e\u003cspan\u003e Gm = 1700 ; Ia = \u003cmeta charset=\"utf-8\"\u003e1.3 mA\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\u003cdiv\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/div\u003e\u003cul\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eBurn-in \/ Stability Test:\u003c\/strong\u003e 48h – OK\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e Low. Tested and compliant for use in hi-fi equipment and guitar amplifiers, even in the most sensitive audio stages.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eBalance:\u003c\/strong\u003e Very good. The sections are consistent and well-aligned, making the tube also suitable for use as a phase inverter in hi-fi and instrumental applications.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eEmission Quality:\u003c\/strong\u003e Excellent – Very strong and stable emission, without fluctuations.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eShorts and GAS:\u003c\/strong\u003e Absent.\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003ePrecious \u003cstrong\u003eMatched Pair of 12AX7 \/ ECC83 NOS EVERETT produced by Philips in the Heerlen plant\u003c\/strong\u003e, authentic Dutch production from \u003cstrong\u003e1964\u003c\/strong\u003e, characterized by the classic \u003cstrong\u003eShort Gray Plates with Halo Getter\u003c\/strong\u003e construction. The manufacturing code \u003cstrong\u003eΔ4K3\u003c\/strong\u003e indeed traces the production to the historic \u003cstrong\u003ePhilips plant in Heerlen, Holland\u003c\/strong\u003e, in November 1964.\u003cspan\u003e\u003c\/span\u003e\u003c\/p\u003e\u003cp\u003eThe tubes branded \u003cstrong\u003eEVERETT\u003c\/strong\u003e therefore feature original Philips Heerlen construction, particularly interesting for enthusiasts of vintage European ECC83s and for those seeking the character and construction quality of Dutch productions from the 1960s.\u003c\/p\u003e\u003cp\u003eThe pair has been carefully tested and selected in our laboratory using the \u003cstrong\u003eAmplitrex AT-1000 Tube Tester\u003c\/strong\u003e, obtaining a \u003cstrong\u003eVERY STRONG\u003c\/strong\u003e classification. The transconductance values of the four sections are between \u003cstrong\u003e1600 and 1800\u003c\/strong\u003e, with extremely consistent anodic currents between \u003cstrong\u003e1.1 and 1.3 mA\u003c\/strong\u003e. The \u003cstrong\u003ebalance is very good\u003c\/strong\u003e and the pair has also been selected for \u003cstrong\u003eLow Noise \u0026amp; Microphonics\u003c\/strong\u003e, with strong, stable emission and free from anomalies.\u003cspan\u003e\u003c\/span\u003e\u003c\/p\u003e\u003cp\u003eSonically, the Philips Heerlen ECC83s are particularly appreciated for a refined and musical reproduction, capable of combining warmth and naturalness with remarkable openness and definition. The mid-range is rich and articulate, the bass well-controlled, and the high frequencies detailed without being aggressive, with a wide and well-focused soundstage.\u003c\/p\u003e\u003cp\u003eIdeal for \u003cstrong\u003ehi-fi preamplifiers, phono stages, integrated amplifiers, tube DACs, and guitar amplifiers\u003c\/strong\u003e compatible with \u003cstrong\u003e12AX7 \/ ECC83\u003c\/strong\u003e. Thanks to the \u003cstrong\u003eLow Noise \u0026amp; Microphonics\u003c\/strong\u003e selection, they are particularly interesting even in the most sensitive audio stages, while the excellent balance of the sections further expands their possibilities of use.\u003c\/p\u003e\u003cp\u003eThe tubes are \u003cstrong\u003eNOS – New Old Stock\u003c\/strong\u003e, accurately tested and perfectly functional. The aesthetic conditions are good, with partially faded but still legible silkscreen printing, consistent with the age of the specimens.\u003cspan\u003e\u003c\/span\u003e\u003c\/p\u003e\u003cp\u003eA valuable \u003cstrong\u003eMatched Pair of EVERETT by Philips Heerlen 12AX7 \/ ECC83 from 1964\u003c\/strong\u003e, genuinely tested and selected by \u003cstrong\u003eVacuum Tubes Treasures\u003c\/strong\u003e, ideal for those seeking authentic NOS Dutch ECC83s, strong, well-balanced, and selected for \u003cstrong\u003eLow Noise \u0026amp; Microphonics\u003c\/strong\u003e.\u003cstrong\u003e\u003c\/strong\u003e\u003c\/p\u003e\u003chr\u003e\u003ch3\u003e\u003cstrong\u003eConditions:\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cli\u003e\n\u003cstrong\u003eCondition:\u003c\/strong\u003e NOS - New Old Stock - Tested and functional - Supplied in our custom box for optimal protection. \u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFunctionality: \u003c\/strong\u003ePerfectly operational.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAesthetic conditions:\u003c\/strong\u003e Good – Markings partially faded, but still legible. Tube body in good condition. See photos for details.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturing Code:\u003c\/strong\u003e ???  Δ4K3 (Barely perceptible on one tube, absent on the other) - Δ → Heerlen (Holland), 4 (out of four digits) → 1964 - K → November 3 \u003cmeta charset=\"utf-8\"\u003e→ Third week of the month\u003cbr\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\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\u003eDiscover why our tubes are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"PHILIPS","offers":[{"title":"Default Title","offer_id":58892030214492,"sku":"03772Y","price":179.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_194c36b4-8f58-4e5e-9899-6f5ac19b3a76.jpg?v=1788250479","url":"https:\/\/vacuumtubestreasures.com\/en-si\/products\/12ax7-ecc83-nos-philips-heerlen-1964-short-gray-plates-halo-getter-amplitrex-tested","provider":"Vacuum Tubes Treasures","version":"1.0","type":"link"}