{"product_id":"12ax7-ecc83-mazda-valve-tested-pair-same-date-codes-short-gray-plates-halo-getter-made-in-england-bva-copia","title":"12AX7 \/ ECC83 MULLARD Blackburn Short Gray Plates Halo Getter - Same Code I61 B1C - AMPLITREX Tested Pair - Low Noise \u0026 Microphonics","description":"\u003cp class=\"p1\"\u003e\u003cb\u003e12AX7 \/ ECC83 Mullard Blackburn – Selected Pair – Same 3-Character Code I61 B1C – Short Gray Plates – Halo Getter – Made in Great Britain\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p2\"\u003e\u003cb\u003eAMPLITREX Tested – Low Noise \u0026amp; Microphonics – Early Blackburn Production – Selected Vintage Pair\u003c\/b\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eDescription\u003c\/b\u003e\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp class=\"p1\"\u003eThis pair of \u003cspan class=\"s1\"\u003e\u003cb\u003e12AX7 \/ ECC83 Mullard Blackburn\u003c\/b\u003e\u003c\/span\u003e, \u003cspan class=\"s1\"\u003e\u003cb\u003eMade in Great Britain\u003c\/b\u003e\u003c\/span\u003e production, represents a vintage selection of particular historical and technical appeal, belonging to early British Mullard Blackburn productions.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eBoth tubes bear the same engraved code \u003cspan class=\"s1\"\u003e\u003cb\u003eI61 B1C\u003c\/b\u003e\u003c\/span\u003e, a very interesting element for manufacturing consistency and production origin. The 3-character date code \u003cspan class=\"s1\"\u003e\u003cb\u003eB1C\u003c\/b\u003e\u003c\/span\u003e refers to a very early Blackburn production from 1951, a period highly sought after today by enthusiasts of vintage British ECC83s.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eThe construction with \u003cspan class=\"s1\"\u003e\u003cb\u003eshort gray plates\u003c\/b\u003e\u003c\/span\u003e and a \u003cspan class=\"s1\"\u003e\u003cb\u003etop halo getter\u003c\/b\u003e\u003c\/span\u003e recalls the classic British Mullard architecture, known for musicality, tonal balance, and natural sound presentation.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eThis pair is offered as a \u003cspan class=\"s1\"\u003e\u003cb\u003eSelected Vintage Pair\u003c\/b\u003e\u003c\/span\u003e and not as a precision matched pair. The two tubes share the same production origin, the same internal structure, and the same manufacturing code, despite presenting electrical values that are not perfectly identical, an aspect absolutely consistent with authentic used vintage Mullard Blackburns over seventy years old.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eThe tubes have been carefully tested and selected using the \u003cspan class=\"s1\"\u003e\u003cb\u003eAMPLITREX AT-1000 Tube Tester\u003c\/b\u003e\u003c\/span\u003e, with particular attention to quietness, microphonics, and operational stability. Both showed regular behavior, low microphonics, and no GAS or short circuits.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eAesthetically, they are in good condition, consistent with their age: there are signs of time, wear of the silk-screening, and an authentically lived-in appearance, but overall they remain very presentable and visually appealing.\u003c\/p\u003e\n\u003ch3\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eSonic Characteristics\u003c\/b\u003e\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp class=\"p1\"\u003eThe early Mullard Blackburn ECC83s are renowned for a musical, textured, and natural sound presentation, capable of combining harmonic richness, fluidity, and a particular sense of organic quality.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eThis pair clearly retains the typical character of the British Mullard school: a credible, warm yet balanced sound, with refined harmonic texture and consistently musical response.\u003c\/p\u003e\n\u003cp\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eBass\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eThe bass range is natural, composed, and well-articulated. The bass maintains a good presence without becoming intrusive, contributing to a stable and coherent sound presentation.\u003c\/p\u003e\n\u003cp\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eMidrange\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eThe midrange represents the true strength of this early Blackburn production. Vocals emerge with naturalness and texture, while acoustic instruments and harmonics retain a rich, fluid, and credible texture.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eIt possesses that typical vintage British musicality that has made Mullard ECC83s particularly appreciated in both hi-fi and musical contexts.\u003c\/p\u003e\n\u003cp\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eTreble\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eThe treble range is sweet, refined, and well-integrated. Detail remains present without aggressiveness, with a reproduction that favors long and relaxed listening sessions.\u003c\/p\u003e\n\u003cp\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eDynamics\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eThe dynamic response is fluid and progressive, with good readability of musical variations and a consistently composed and natural presentation.\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 stable and well-organized, with good instrument separation and credible depth. The reproduction remains musical and coherent, without artificiality.\u003c\/p\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=\"p1\"\u003eThese Mullard Blackburn ECC83 \/ 12AX7 are particularly suitable for:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003ehi-fi preamplifiers;\u003c\/li\u003e\n\u003cli\u003eline stages;\u003c\/li\u003e\n\u003cli\u003ephono stages;\u003c\/li\u003e\n\u003cli\u003edriver stages;\u003c\/li\u003e\n\u003cli\u003evintage and modern systems compatible with ECC83 \/ 12AX7.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"p3\"\u003eThe \u003cspan class=\"s1\"\u003e\u003cb\u003eLow Noise \u0026amp; Microphonics\u003c\/b\u003e\u003c\/span\u003e selection also makes them suitable for sensitive circuit positions, including phono applications and high-gain configurations.\u003c\/p\u003e\n\u003cp class=\"p4\"\u003eThe tubes have also been verified as suitable for use in the \u003cspan class=\"s1\"\u003e\u003cb\u003eV1\u003c\/b\u003e\u003c\/span\u003e position.\u003c\/p\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=\"p1\"\u003eIn guitar amplifiers and musical applications, this Mullard Blackburn pair can offer a harmonically rich response, expressive mids, and a very natural musical presentation.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eBritish Mullard ECC83s are historically appreciated in vintage and boutique circuits for their ability to maintain musicality, fluidity, and a consistently controlled high range.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eLow microphonics and good operational stability also make them suitable for compatible professional uses.\u003c\/p\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=\"p1\"\u003eThis pair represents a particularly interesting selection for those who desire authentic \u003cspan class=\"s1\"\u003e\u003cb\u003eMullard Blackburn ECC83 \/ 12AX7\u003c\/b\u003e\u003c\/span\u003e with:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003esame engraved production code \u003cspan class=\"s1\"\u003e\u003cb\u003eI61 B1C\u003c\/b\u003e\u003c\/span\u003e;\u003c\/li\u003e\n\u003cli\u003every early Blackburn production;\u003c\/li\u003e\n\u003cli\u003eshort gray plates construction;\u003c\/li\u003e\n\u003cli\u003ehalo getter;\u003c\/li\u003e\n\u003cli\u003elow noise \u0026amp; microphonics selection;\u003c\/li\u003e\n\u003cli\u003etypical vintage British Mullard musicality.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"p3\"\u003eThis is not a precision matched pair, but a vintage pair selected for production consistency, homogeneous internal structure, and overall operational quality.\u003c\/p\u003e\n\u003cp class=\"p4\"\u003eA solution with strong historical and sonic appeal, designed for those who wish to integrate the authentic character of the early Mullard Blackburns into their system, while maintaining full technical credibility and professional selection.\u003c\/p\u003e\n\u003chr\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\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 \u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eTube #1:\u003c\/strong\u003e STRONG\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSection 1:\u003c\/strong\u003e\u003cspan\u003e Gm = 1200 ; Ia = 0.8 mA\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSection 2:\u003c\/strong\u003e\u003cspan\u003e Gm = 1400 ; Ia = 0.9 mA\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eTube #2: \u003c\/strong\u003e\u003cmeta charset=\"utf-8\"\u003eVERY STRONG\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSection 1:\u003c\/strong\u003e\u003cspan\u003e Gm = 1300 ; Ia = 0.9 mA\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSection 2:\u003c\/strong\u003e\u003cspan\u003e Gm = 1700 ; Ia = 1.3 mA\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cdiv\u003e\u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cstrong\u003e\u003c\/strong\u003e\u003cbr\u003e\n\u003c\/div\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMicrophonics:\u003c\/strong\u003e Low. Tested and suitable for hi-fi use, including phono stages and guitar amplifiers. Also suitable for V1.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNoise:\u003c\/strong\u003e Low and well controlled. Quiet operation in hi-fi and musical amplifiers in designated positions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBalance:\u003c\/strong\u003e Sections do not have perfectly coinciding values, an aspect consistent with an authentic selected vintage pair. The pair remains fully interesting for hi-fi and musical use in compatible circuits.\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eEmission Quality:\u003c\/strong\u003e Strong – Strong and regular emission, suitable for any application.\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\n\u003cstrong\u003eCondition:\u003c\/strong\u003e Vintage Tubes - Tested and fully 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\u003eFully operational.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAesthetic Condition:\u003c\/strong\u003e Good and consistent with age. Shows signs of time, light wear of the silk-screening, and normal vintage patina. See photos for details.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eManufacturing Code: \u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eI61 B1C → I6x indicates an ECC83 with sequential progression x, where the increment of x indicates production changes - B1C B → Mullard, Blackburn - 1 (out of three digits) → 1951 - C → March\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003ca rel=\"noopener\" title=\"Perché le nostre valvole sono diverse – il protocollo VTT che migliora suono, affidabilità e durata\" 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":"MULLARD","offers":[{"title":"Default Title","offer_id":57642356932956,"sku":"03597","price":29300.0,"currency_code":"ISK","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_d015c9fd-3903-41a0-a166-beea75eb1381.jpg?v=1778686072","url":"https:\/\/vacuumtubestreasures.com\/en-is\/products\/12ax7-ecc83-mazda-valve-tested-pair-same-date-codes-short-gray-plates-halo-getter-made-in-england-bva-copia","provider":"Vacuum Tubes Treasures","version":"1.0","type":"link"}