{"product_id":"12ax7-ecc83-toshiba-long-gray-plates-halo-getter-low-noise-mic-tube-1960s","title":"12AX7 \/ ECC83 TOSHIBA Long Gray Plate Halo Getter Low-Noise Microphone Tube 1960s","description":"\u003ch3 data-pm-slice=\"1 1 []\"\u003e\u003cstrong\u003e12AX7 \/ ECC83 TOSHIBA Long Gray Plates Halo Getter Tube Made in JAPAN 1960s\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-pm-slice=\"1 1 []\"\u003e\u003cstrong\u003e\u003cb\u003eAMPLITREX Tested \u003cmeta charset=\"utf-8\"\u003e– \u003cmeta charset=\"utf-8\"\u003e \u003cspan\u003eRed Dot \u003c\/span\u003e– Low Noise \u0026amp; Microphonics – Vintage Japanese TOSHIBA Production\u003c\/b\u003e\u003c\/strong\u003e\u003cstrong\u003e\u003cb\u003e\u003c\/b\u003e\u003c\/strong\u003e\u003cstrong\u003e\u003cb\u003e\u003c\/b\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eTube tested on \u003cstrong\u003eAMPLITREX AT-1000 \u003c\/strong\u003eTube Tester:\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eTest Conditions:\u003c\/strong\u003e\u003cspan\u003e Va = 250V ; Vg = -2V\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003e100% Average:\u003c\/strong\u003e\u003cspan\u003e \u003cmeta charset=\"utf-8\"\u003eGm = 1600 ; Ia = 1.2 mA\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eTest Result:\u003c\/strong\u003e VERY STRONG\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eTube:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eSection 1:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eGm = 1700 ; Ia = 1.3 mA\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eSection 2:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eGm = \u003cmeta charset=\"utf-8\"\u003e1500 ; Ia = \u003cmeta charset=\"utf-8\"\u003e1.0 mA\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cdiv\u003e\n\n\u003cmeta charset=\"utf-8\"\u003e\n\n\u003cdiv\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/div\u003e\n\n\u003cul\u003e\n\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eBurn-in \/ Stability Test:\u003c\/strong\u003e 48h – OK\u003c\/span\u003e\u003c\/li\u003e\n\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e Ultra Low. Tested and suitable for use in hi-fi equipment and guitar amplifiers, including the most sensitive audio stages.\u003c\/span\u003e\u003c\/li\u003e\n\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eBalance:\u003c\/strong\u003e The sections are not perfectly aligned. The tube is recommended for hi-fi use in non-critical stages (input or driver) and in guitar amplifiers. Not recommended as a phase inverter or in applications requiring strict balance between the sections.\u003c\/span\u003e\u003c\/li\u003e\n\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\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eShort Circuits and GAS:\u003c\/strong\u003e None.\u003c\/span\u003e\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\n\u003c\/div\u003e\n\u003ch3\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-pm-slice=\"1 1 []\"\u003e\u003cspan\u003eSelected vintage specimen of \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e12AX7 \/ ECC83 Toshiba\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, attributed to Japanese production from the \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e1960s\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e based on construction characteristics. The tube features the characteristic \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eLong Gray Plates with Halo Getter\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e configuration, accompanied by a distinctive internal structure and the recognizable top in red glass. An interesting specimen of the Japanese thermionic tradition, intended for audiophiles and musicians seeking vintage tubes with documented electrical characteristics and a particularly careful selection in terms of noise.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eMeasurements carried out with \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eAmplitrex AT-1000\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e show \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eVERY STRONG\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e emission, with transconductances of \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e1700 and 1500 µmhos\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e in their respective sections, corresponding to 106.25% and 93.75% of the nominal reference of 1600. The average therefore reaches \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e1600 µmhos\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, exactly matching the reference value. The anode currents measure \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e1.3 and 1.0 mA\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e respectively, with an average of \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e1.15 mA\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, very close to the nominal reference of 1.2 mA. The two sections show an appreciable electrical difference, clearly documented by the measurements, while both maintain fully valid performance.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe tube has passed \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e48 hours of burn-in and stability testing\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, maintaining a very strong and even emission, without fluctuations, short circuits, or the presence of gas. A particularly significant element is represented by the \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eextremely low microphonics\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, confirmed by the special \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eRed Dot\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e selection. This characteristic makes the specimen particularly interesting for the most sensitive audio stages, in which silence and stability are fundamental requirements.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e12AX7 \/ ECC83 Long Gray Plates\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e find application in hi-fi preamplifiers, compatible phono stages, and guitar amplifiers, especially in the input and signal amplification stages. Given the electrical difference between the two sections, this specimen \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eis not recommended for phase inverter circuits or applications requiring strict balance\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e. Vintage Japanese thermionic production is traditionally appreciated by audiophiles for a musical presentation generally described as \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003edetailed, balanced, and dynamic\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, with good articulation of the midrange and a pleasant tonal naturalness.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe value of this specimen lies in the \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eLong Gray Plates construction\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, in the very strong electrical performance and, above all, in the \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eRed Dot selection with extremely low microphonics\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e. Although the original screen printing states \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eMade in Holland\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, the construction characteristics lead to attributing the tube to Japanese Toshiba production. The absence of a decipherable manufacturing code does not, however, allow us to document its exact origin and year. The well-preserved markings and very good aesthetic condition complete an interesting vintage specimen, carefully tested and selected, for those seeking a \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003evintage 12AX7 with documented performance, verified stability, and extremely low noise\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e.\u003c\/span\u003e\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eCondition:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eCondition: \u003c\/strong\u003eVintage Tubes - Tested and perfectly functioning. Supplied in our custom box for optimal protection. \u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eFunctionality: \u003c\/strong\u003ePerfectly operational.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eAesthetic condition:\u003c\/strong\u003e Very Good – Markings clearly legible with slight signs of age. See photos for details.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eSpecial selection: \u003c\/strong\u003eRed Dot, with low noise and microphonics verified using Amplitrex AT-1000.\u003c\/li\u003e\n\n\u003cli\u003e\n\n\u003cstrong\u003eManufacturing Code: \u003c\/strong\u003eCode not decipherable. Although the screen printing states Made in Holland, it is clearly a production attributable to TOSHIBA Japan, approximately from the 1960s based on the construction characteristics.\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\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 longevity\" rel=\"noopener\" target=\"_blank\"\u003e\u003cstrong\u003eDiscover why our tubes are different →\u003c\/strong\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"TOSHIBA","offers":[{"title":"Default Title","offer_id":59835975598428,"sku":"03926","price":49.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/10_106aef5e-5db4-44e9-b39c-b5aea4d0a7d9.jpg?v=1794336577","url":"https:\/\/vacuumtubestreasures.com\/en-pt\/products\/12ax7-ecc83-toshiba-long-gray-plates-halo-getter-low-noise-mic-tube-1960s","provider":"Vacuum Tubes Treasures","version":"1.0","type":"link"}