{"product_id":"12x4-rca-nos-nib-matched-pair-black-plates-foil-getter-tubes-rectifiers-made-in-usa-58","title":"12X4 RCA NOS NIB Matched Pair Black Plates Foil Getter Tubes Rectifiers Made in USA '58","description":"\u003cp\u003e\u003cstrong\u003e12X4 RCA NOS NIB Matched Pair Black Plates Foil Getter Tubes Rectifiers Made in USA '58\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-end=\"514\" data-start=\"141\"\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cmeta charset=\"utf-8\"\u003e The 12X4 RCAs with \u003cstrong data-end=\"251\" data-start=\"235\"\u003eblack plates\u003c\/strong\u003e and \u003cstrong data-end=\"269\" data-start=\"254\"\u003efoil getters\u003c\/strong\u003e , produced in 1958 in the United States, represent one of the most refined and sought-after versions of this miniature rectifier. Offered in \u003cstrong data-end=\"465\" data-start=\"426\"\u003eNOS NIB (New Old Stock, New In Box)\u003c\/strong\u003e condition and as a \u003cstrong data-end=\"489\" data-start=\"471\"\u003ematched pair\u003c\/strong\u003e , they offer not only the historic RCA build quality but also the guarantee of an ideal match for valuable restorations and high-end hi-fi applications. The foil getter makes them particularly attractive to collectors, adding a rare and distinctive detail to an already valuable set.\u003cbr\u003e\u003c\/p\u003e\n\u003cp data-end=\"546\" data-start=\"516\"\u003e\u003cstrong data-end=\"544\" data-start=\"518\"\u003eSound characteristics\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli data-end=\"933\" data-start=\"821\"\u003e\u003cstrong data-end=\"830\" data-start=\"821\"\u003eBass\u003c\/strong\u003e : dry and well-defined, with a rigorous hold that keeps the low register tidy and precise.\u003c\/li\u003e\n\u003cli data-end=\"1054\" data-start=\"936\"\u003e\u003cstrong data-end=\"944\" data-start=\"936\"\u003eMids\u003c\/strong\u003e : linear and natural, transparent and faithful to the source, with a neutral timbre that does not color the signal.\u003c\/li\u003e\n\u003cli data-end=\"1166\" data-start=\"1057\"\u003e\u003cstrong data-end=\"1065\" data-start=\"1057\"\u003eHighs\u003c\/strong\u003e : Clear and crystalline, with a touch of controlled brilliance that maintains balance and cleanliness.\u003c\/li\u003e\n\u003cli data-end=\"1284\" data-start=\"1169\"\u003e\u003cstrong data-end=\"1181\" data-start=\"1169\"\u003eDynamic\u003c\/strong\u003e : stable and regular, capable of providing continuity of power even under variable conditions.\u003c\/li\u003e\n\u003cli data-end=\"1415\" data-start=\"1287\"\u003e\u003cstrong data-end=\"1301\" data-start=\"1287\"\u003eSoundstage\u003c\/strong\u003e : neutral and quiet, with a clean sound base that allows the qualities of the active tubes to emerge to the fullest.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"1118\" data-end=\"1414\"\u003e🎧 \u003cstrong data-start=\"1121\" data-end=\"1144\"\u003eUse in Hi-Fi Stereo\u003c\/strong\u003e\u003cbr data-start=\"1144\" data-end=\"1147\"\u003e\u003cmeta charset=\"utf-8\"\u003ePerfect for small preamps, tuners, and vintage stereo systems from the 1950s and 1960s, these matched RCA rectifiers offer quiet operation, stability, and tonal consistency while preserving the authenticity of the original design.\u003cbr\u003e\u003c\/p\u003e\n\u003cp data-start=\"1416\" data-end=\"1653\"\u003e🎸 \u003cstrong data-start=\"1419\" data-end=\"1452\"\u003eUse in Music Amplifiers\u003c\/strong\u003e\u003cbr data-start=\"1452\" data-end=\"1455\"\u003e\u003cmeta charset=\"utf-8\"\u003e Also popular in vintage electronic instruments and amplifiers, the 12X4 RCAs ensure a smooth and even power supply, contributing to a faithful, stable sound free from unwanted compression.\u003cbr\u003e\u003c\/p\u003e\n\u003cp data-start=\"1655\" data-end=\"1982\"\u003e🎯 \u003cstrong data-start=\"1658\" data-end=\"1690\"\u003eNote for audiophiles and technicians\u003c\/strong\u003e\u003cbr data-start=\"1690\" data-end=\"1693\"\u003e\u003cmeta charset=\"utf-8\"\u003eThis \u003cstrong data-end=\"2006\" data-start=\"1995\"\u003ematched\u003c\/strong\u003e pair with \u003cstrong data-end=\"2041\" data-start=\"2011\"\u003efoil getters and black plates\u003c\/strong\u003e , dating from 1958, is a rare and highly desirable set. RCAs from this period are universally recognized for their robustness, quiet operation, and neutral sound quality: a real opportunity for collectors, restorers, and enthusiasts seeking the true \"American voice\" of the golden years.\u003cbr\u003e\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eValve tested on Funke W19 Tube Tester:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eTest Conditions:\u003c\/strong\u003e Va = 60V, Vf = 6.3V\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eAverage 100%:\u003c\/strong\u003e Ia =\u003cmeta charset=\"utf-8\"\u003e 42 mA\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eTest Result:\u003c\/strong\u003e VERY STRONG\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cmeta charset=\"utf-8\"\u003eValve 1:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eSection 1:\u003c\/strong\u003e Ia = 47 mA\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eSection 2:\u003c\/strong\u003e Ia = 47 mA\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eValve 2:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eSection 1:\u003c\/strong\u003e Ia = 46 mA\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eSection 2:\u003c\/strong\u003e Ia = 45 mA\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\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 Very\u003c\/span\u003e \u003cmeta charset=\"utf-8\"\u003eLow. Tested and approved for use in hi-fi and guitar amplifiers.\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 NOS - NIB - New Old Stock, New In Box - Tested and working - Supplied in original box.\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 Very good – Clearly legible writing with minor signs of wear, no obvious defects. See photos for details.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eManufacturing Code:\u003c\/strong\u003e KS → two-letter code\u003cmeta charset=\"utf-8\"\u003e → production January 1958\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\u003c\/p\u003e","brand":"RCA","offers":[{"title":"Default Title","offer_id":55498891559260,"sku":"03125Z","price":89.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/1_f6c52661-cb7d-423f-a82b-b3e3154e2e2b.jpg?v=1758131751","url":"https:\/\/vacuumtubestreasures.com\/en-hr\/products\/12x4-rca-nos-nib-matched-pair-black-plates-foil-getter-tubes-rectifiers-made-in-usa-58","provider":"Vacuum Tubes Treasures","version":"1.0","type":"link"}