{"product_id":"5u4gb-5as4a-rca-black-plates-tested-tube-top-side-square-getter-rectifier-made-in-usa-60s","title":"5U4GB 5AS4A RCA Black Plates Tall Bottle Tested Tube Top Side Square Getter Rectifier Made in USA '60s","description":"\u003cp\u003e\u003cstrong\u003e5U4GB 5AS4A RCA Black Plates Tall Bottle Tested Tube Top Side Square Getter Rectifier Made in USA '60s\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003e \u003cem\u003eNote: This unit has a visible chip on the Bakelite base, as shown in the photographs. This is purely cosmetic and does not affect the valve's function, safety, electrical performance, or sonic accuracy. The price fully reflects the aesthetic condition described above.\u003c\/em\u003e\u003c\/p\u003e\n\n\u003ch3\u003e \u003cstrong\u003eDescription:\u003c\/strong\u003e\n\u003c\/h3\u003e\n\n\u003cp data-end=\"671\" data-start=\"196\"\u003e The \u003cstrong data-end=\"220\" data-start=\"199\"\u003e5U4GB \/ 5AS4A RCA\u003c\/strong\u003e , in this \u003cstrong data-end=\"256\" data-start=\"241\"\u003eTall Bottle\u003c\/strong\u003e version with \u003cstrong data-end=\"277\" data-start=\"261\"\u003eblack plates\u003c\/strong\u003e and \u003cstrong data-end=\"299\" data-start=\"280\"\u003esquare getter\u003c\/strong\u003e in the \u003cstrong data-end=\"337\" data-start=\"313\"\u003eupper and lateral\u003c\/strong\u003e position, represents one of the most robust and balanced rectifiers of the American production of the 60s. \u003cbr data-end=\"440\" data-start=\"437\"\u003eThe tall bottle is often associated with greater thermal dissipation and a more generous construction, useful for ensuring \u003cstrong data-end=\"670\" data-start=\"581\"\u003ereliability and stability even in prolonged or high current demand applications\u003c\/strong\u003e .\u003c\/p\u003e\n\n\u003cp data-end=\"949\" data-start=\"673\"\u003e \u003cstrong data-end=\"682\" data-start=\"673\"\u003eBass\u003c\/strong\u003e : Solid and well-controlled. The low range is notable for its firmness and articulation, without ever becoming intrusive. The power control provides a compact and coherent sound base, essential for systems that focus on detail and dynamics.\u003c\/p\u003e\n\n\u003cp data-end=\"1205\" data-start=\"951\"\u003e \u003cstrong data-end=\"959\" data-start=\"951\"\u003eMids\u003c\/strong\u003e : Natural, tidy, and slightly restrained. Voices integrate precisely into the soundscape, without unnatural projection. The typical RCA mids are recognized for their clarity and transparency, which are also very present in this tall bottle version.\u003c\/p\u003e\n\n \u003cp data-end=\"1414\" data-start=\"1207\"\u003e\u003cstrong data-end=\"1215\" data-start=\"1207\"\u003eHighs\u003c\/strong\u003e : Clean and silky. The high-range response is measured, never exuberant. Details emerge without harshness, with a restrained brilliance that enhances musicality and reduces listening fatigue.\u003c\/p\u003e\n\n\u003cp data-end=\"1640\" data-start=\"1416\"\u003e \u003cstrong data-end=\"1428\" data-start=\"1416\"\u003eDynamics\u003c\/strong\u003e : Wide and smooth. The valve consistently follows both micro-variations and the most energetic transients, without introducing compression or instability. Behavior under load is progressive and well-controlled.\u003c\/p\u003e\n\n\u003cp data-end=\"1878\" data-start=\"1642\"\u003e \u003cstrong data-end=\"1656\" data-start=\"1642\"\u003eSoundstage\u003c\/strong\u003e : Wide and cohesive. The soundstage is stable and well-layered, with balanced spatial distribution and good depth, suitable for systems that aim for transparent but not overly analytical performance.\u003c\/p\u003e\n\n\u003cp data-end=\"2210\" data-start=\"1880\"\u003e 🎧 \u003cstrong data-end=\"1940\" data-start=\"1883\"\u003eUse in Headphone Amplifiers and Hi-Fi Driver Stages\u003c\/strong\u003e \u003cbr data-end=\"1943\" data-start=\"1940\"\u003eIdeal for tube preamps, tube DACs, and OTL amplifiers, where power control is crucial to achieving stable, clean, and three-dimensional sound. The Tall Bottle structure provides a useful power reserve for demanding configurations.\u003c\/p\u003e\n\n\u003cp data-end=\"2591\" data-start=\"2212\"\u003e 🎸 \u003cstrong data-end=\"2260\" data-start=\"2215\"\u003eUse in Guitar and Bass Amplifiers\u003c\/strong\u003e\u003cbr data-end=\"2263\" data-start=\"2260\"\u003e This RCA version is used in vintage American amplifiers (e.g., \u003cstrong data-end=\"2350\" data-start=\"2329\"\u003eFender Bandmaster\u003c\/strong\u003e , \u003cstrong data-end=\"2368\" data-start=\"2352\"\u003eSuper Reverb\u003c\/strong\u003e , \u003cstrong data-end=\"2381\" data-start=\"2370\"\u003eShowman\u003c\/strong\u003e ) where the rectifier response directly affects feel and articulation. It offers progressive tube compression, with well-managed headroom and an excellent balance between detail and warmth.\u003c\/p\u003e\n\n\u003cp data-end=\"2923\" data-start=\"2593\"\u003e 🎯 \u003cstrong data-end=\"2628\" data-start=\"2596\"\u003eNote for audiophiles and technicians\u003c\/strong\u003e \u003cbr data-end=\"2631\" data-start=\"2628\"\u003eA \u003cstrong data-end=\"2698\" data-start=\"2650\"\u003ereliable, balanced, and musically restrained\u003c\/strong\u003e rectifier, featuring Tall Bottle construction for superior heat dissipation and stable response even in professional or high-current settings. A perfect choice for systems requiring consistency, neutrality, and control.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch3\u003e \u003cstrong\u003eTest Results\u003c\/strong\u003e\n\u003c\/h3\u003e\n\n\u003cp\u003e \u003cstrong\u003eTubes Tested\u003c\/strong\u003e on \u003cstrong\u003eFunke W19\u003c\/strong\u003e Tube Tester:\u003c\/p\u003e\n\n\u003cp\u003e \u003cstrong\u003eVoltage Test:\u003c\/strong\u003e Va = 100V, Vf = 5V \u003cstrong\u003e\u003cbr\u003eGood from:\u003c\/strong\u003e Ia = 78 mA \u003cstrong\u003e\u003cbr\u003eAverage 100%:\u003c\/strong\u003e Ia = 120 mA \u003cstrong\u003e\u003cbr\u003eTEST RESULT:\u003c\/strong\u003e VERY STRONG\u003c\/p\u003e\n\n\u003cp\u003e \u003cstrong\u003eValve\u003c\/strong\u003e :\u003c\/p\u003e\n\n\u003cul\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eSection 1\u003c\/strong\u003e : Ia = 139 mA\u003c\/li\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eSection 2\u003c\/strong\u003e : Ia = 125 mA\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cdiv\u003e\n\n\u003cstrong\u003e\u003c\/strong\u003e\u003cbr\u003e\n\n\u003c\/div\u003e\n\n\u003cdiv\u003e \u003cstrong\u003eAdditional Tests Performed:\u003c\/strong\u003e\n\u003c\/div\u003e\n\n\u003cul\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eOperation:\u003c\/strong\u003e Stable valve, quiet in operation, and suitable for regular and controlled power supply. Tested with a Funke W19 tester.\u003c\/li\u003e\n\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\n\u003cli\u003e \u003cspan\u003e\u003cstrong\u003eShort circuits and GAS:\u003c\/strong\u003e Absent.\u003c\/span\u003e\n\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch3\u003e \u003cstrong\u003eConditions:\u003c\/strong\u003e\n\u003c\/h3\u003e\n\n\u003cul\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eCondition:\u003c\/strong\u003e Vintage tubes - Tested and in perfect working order. Shipped 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\u003e Fully functional.\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eCosmetic condition:\u003c\/strong\u003e \u003cspan\u003eFair – All writing is completely gone, with obvious signs of wear and a chip on the plastic base. See photos for details.\u003c\/span\u003e\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\n\n\u003c\/li\u003e\n\n\u003cli\u003e\n\n \u003cstrong\u003eManufacturing Code:\u003cspan\u003e \u003c\/span\u003e\u003c\/strong\u003eAbsent - Made by RCA USA -\u003cmeta charset=\"utf-8\"\u003e \u003cspan\u003eYear of manufacture missing, detected by the internal structure.\u003cmeta charset=\"utf-8\"\u003e Made in the early 1960s.\u003c\/span\u003e\n\n\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cspan\u003e \u003cmeta charset=\"utf-8\"\u003e\n\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\/span\u003e\u003c\/p\u003e","brand":"RCA","offers":[{"title":"Default Title","offer_id":54729654075740,"sku":"02965","price":238.0,"currency_code":"PLN","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0616\/3775\/5127\/files\/3_7b996b57-aa26-4e51-9ec3-20de25d99cd7.jpg?v=1749632368","url":"https:\/\/vacuumtubestreasures.com\/en-pl\/products\/5u4gb-5as4a-rca-black-plates-tested-tube-top-side-square-getter-rectifier-made-in-usa-60s","provider":"Vacuum Tubes Treasures","version":"1.0","type":"link"}