{"product_id":"5r4gy-international-rca-black-plates-brown-base-hanging-filaments-nos-nib-made-in-usa","title":"5R4GY INTERNATIONAL (RCA) – Black Plates Brown Base – Hanging Filaments – NOS NIB – Made in USA '50s","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cstrong\u003e5R4GY RCA for INTERNATIONAL – Black Plates Brown Base Hanging Filaments Double Square Bottom Getter – Made in USA '50s – NOS NIB\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eDescription:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-start=\"389\" data-end=\"1043\"\u003eThis \u003cstrong data-start=\"396\" data-end=\"405\"\u003e5R4GY\u003c\/strong\u003e , manufactured by \u003cstrong data-start=\"419\" data-end=\"426\"\u003eRCA\u003c\/strong\u003e and rebranded as \u003cstrong data-start=\"441\" data-end=\"470\"\u003eInternational Electronics\u003c\/strong\u003e , is a very high quality rectifier dating from the \u003cstrong data-start=\"535\" data-end=\"548\"\u003e1954–1957\u003c\/strong\u003e period, when RCA production was at its technical peak. \u003cbr data-start=\"608\" data-end=\"611\"\u003eThe combination of \u003cstrong data-start=\"630\" data-end=\"676\"\u003ethick black plates with rounded corners\u003c\/strong\u003e , \u003cstrong data-start=\"678\" data-end=\"737\"\u003edouble square bottom getter\u003c\/strong\u003e , \u003cstrong data-start=\"739\" data-end=\"780\"\u003ehanging filaments\u003c\/strong\u003e and \u003cstrong data-start=\"783\" data-end=\"812\"\u003ebrown Bakelite base\u003c\/strong\u003e unmistakably identifies it as a mid-50s RCA origin.\u003cbr data-start=\"873\" data-end=\"876\"\u003eAbsent are the rivets or stitching characteristic of later versions, a distinctive sign of the \u003cstrong data-start=\"974\" data-end=\"1023\"\u003efully industrial\/military manufacturing\u003c\/strong\u003e typical of the period.\u003c\/p\u003e\n\u003cp data-start=\"1045\" data-end=\"1398\"\u003eThe \u003cstrong data-start=\"1056\" data-end=\"1073\"\u003eInternational\u003c\/strong\u003e brand was not a manufacturer but a distributor active between the 60s and 70s, which purchased valves from \u003cstrong data-start=\"1168\" data-end=\"1190\"\u003eRCA, Sylvania or GE\u003c\/strong\u003e , tested them and rebranded them. \u003cbr data-start=\"1220\" data-end=\"1223\"\u003eTherefore, the commercial branding may be misleading, but the internal structure is \u003cstrong data-start=\"1309\" data-end=\"1331\"\u003e100% original RCA\u003c\/strong\u003e , belonging to the most valuable and robust generation of the 5R4GY.\u003c\/p\u003e\n\u003ch3 data-start=\"1400\" data-end=\"1441\"\u003eSound and Technical Characteristics\u003c\/h3\u003e\n\u003cp data-start=\"1442\" data-end=\"2075\"\u003e\u003cstrong data-start=\"1442\" data-end=\"1452\"\u003eBass:\u003c\/strong\u003e extended and controlled, with a full and authoritative impression; excellent sense of solidity and absence of bloat.\u003cbr data-start=\"1564\" data-end=\"1567\"\u003e\u003cstrong data-start=\"1567\" data-end=\"1576\"\u003eMids:\u003c\/strong\u003e amber and natural, with typical RCA body and musicality; voices emerge warm and well-centered.\u003cbr data-start=\"1675\" data-end=\"1678\"\u003e\u003cstrong data-start=\"1678\" data-end=\"1687\"\u003eHighs:\u003c\/strong\u003e Smooth, airy, and velvety, with impeccable tonal balance; they deliver detail and spaciousness without straining the listener.\u003cbr data-start=\"1814\" data-end=\"1817\"\u003e\u003cstrong data-start=\"1817\" data-end=\"1830\"\u003eDynamics:\u003c\/strong\u003e stable and balanced, with smooth energy release and excellent transient control. \u003cbr data-start=\"1924\" data-end=\"1927\"\u003e\u003cstrong data-start=\"1927\" data-end=\"1942\"\u003eSoundstage:\u003c\/strong\u003e Deep and realistic, with a cohesive, three-dimensional soundstage; the coherence between planes is typical of vintage RCA rectifiers.\u003c\/p\u003e\n\u003ch3 data-start=\"2077\" data-end=\"2112\"\u003e🎧 Use in Hi-Fi Amplifiers\u003c\/h3\u003e\n\u003cp data-start=\"2113\" data-end=\"2386\"\u003eIdeal for \u003cstrong data-start=\"2138\" data-end=\"2167\"\u003evintage hi-fi and broadcast\u003c\/strong\u003e amplifiers (McIntosh, Fisher, Dynaco, RCA), where it provides a \u003cstrong data-start=\"2218\" data-end=\"2279\"\u003esmooth, musical rectification rich in natural harmonics\u003c\/strong\u003e .\u003cbr data-start=\"2280\" data-end=\"2283\"\u003eIt contributes to a smoother sound, with a greater sense of depth and control in the low frequencies.\u003c\/p\u003e\n\u003ch3 data-start=\"2388\" data-end=\"2426\"\u003e🎸 Use in Music Amplifiers\u003c\/h3\u003e\n\u003cp data-start=\"2427\" data-end=\"2632\"\u003eExcellent for \u003cstrong data-start=\"2456\" data-end=\"2481\"\u003eguitar or studio-grade\u003c\/strong\u003e amplifiers using 5R4 rectifiers, it offers a smooth yet responsive response with natural attack and musical sustain, perfect for warm, dynamic tones.\u003c\/p\u003e\n\u003ch3 data-start=\"2634\" data-end=\"2671\"\u003e🎯 Note for Audiophiles and Technicians\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli data-start=\"2674\" data-end=\"2771\"\u003e\u003cstrong data-start=\"2674\" data-end=\"2710\"\u003eReal RCA production (1954–1957)\u003c\/strong\u003e , rebranded \u003cstrong data-start=\"2724\" data-end=\"2753\"\u003eInternational Electronics\u003c\/strong\u003e in the 1960s.\u003c\/li\u003e\n\u003cli data-start=\"2774\" data-end=\"2913\"\u003e\u003cstrong data-start=\"2774\" data-end=\"2801\"\u003eFull-spec RCA construction\u003c\/strong\u003e with \u003cstrong data-start=\"2806\" data-end=\"2822\"\u003eblack plates\u003c\/strong\u003e , \u003cstrong data-start=\"2824\" data-end=\"2845\"\u003ehanging filaments\u003c\/strong\u003e , \u003cstrong data-start=\"2847\" data-end=\"2878\"\u003edouble square bottom getter\u003c\/strong\u003e and \u003cstrong data-start=\"2881\" data-end=\"2910\"\u003ebrown Bakelite base\u003c\/strong\u003e .\u003cbr\u003e\u003c\/li\u003e\n\u003cli data-start=\"3000\" data-end=\"3077\"\u003e\u003cstrong data-start=\"3000\" data-end=\"3011\"\u003eNOS NIB\u003c\/strong\u003e , never used, kept in original International box.\u003c\/li\u003e\n\u003cli data-start=\"3080\" data-end=\"3165\"\u003e\u003cstrong data-start=\"3080\" data-end=\"3114\"\u003eReliability and sound consistency\u003c\/strong\u003e typical of the best American grinders.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003e\u003cstrong\u003eTest Results:\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eValve tested on \u003cstrong\u003eFunke W19\u003c\/strong\u003e Tube Tester:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eTest Conditions:\u003c\/strong\u003e \u003cspan\u003eVa = 100V ; Vf = 5.0V\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cstrong\u003eGood from:\u003c\/strong\u003e Ia = 61 mA\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eAverage 100%:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eIa = 95 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\u003eValve:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eSection 1:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eIa = 105 mA\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eSection 2:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eIa = 100 mA\u003c\/li\u003e\n\u003c\/ul\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\u003cmeta charset=\"utf-8\"\u003e Standard. Tested and approved for use in hi-fi and guitar amplifiers.\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 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\u003eCosmetic condition:\u003c\/strong\u003e Excellent – Excellently preserved lettering, minimal signs of wear. See photos for details.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eManufacturing Code:\u003c\/strong\u003e absent – RCA USA production, identifiable by construction features\u003cmeta charset=\"utf-8\"\u003e period \u003cstrong data-start=\"535\" data-end=\"548\"\u003e1954–1957\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong data-start=\"535\" data-end=\"548\"\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\/strong\u003e\u003c\/p\u003e","brand":"RCA","offers":[{"title":"Default Title","offer_id":55747370975580,"sku":"03203","price":94.9,"currency_code":"EUR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/3_de3ebcbb-f48b-457e-bd65-f06f30dd8836.jpg?v=1760685827","url":"https:\/\/vacuumtubestreasures.com\/en-hr\/products\/5r4gy-international-rca-black-plates-brown-base-hanging-filaments-nos-nib-made-in-usa","provider":"Vacuum Tubes Treasures","version":"1.0","type":"link"}