Description

Historic TubeMuseum, Tuxedo Park, New York Established in 1928 as a premier research facility in Tuxedo Park, New York, that attracted such brilliant and most visionary minds of the twentieth century - Albert Einstein, Werner Heisenberg, James Franck, Niels Bohr and Enrico Fermi to name a few. The Tuxedo Park lab attracted these top-flight scientists who experimented with audio, sound, time measurement, and radar (first klystron tube). Welcome to the ... TUBE MUSEUM NEW YORK Last Pair "TESTING like OUT OF A 1950's TIME-CAPSULE" 6SN7-GT tubes available "NEW OLD STOCK "USA SYLVANIA 6SN7GT "FLAT" BLACK-PLATE AUDIO TUBE, excellent lush sounding, very rare black-plates from the USA, same tube construction was made for the United States Military but labeled VT231 WITH THE DESIGN. These rival the RCA 5692 redbase in sound and black-plate construction quality, and are as scarce. Sylvania labels, the construction of these to me look to be ENGINEERED VERY WELL AND NEVER TO BE MADE AGAIN!. VERY difficult to find these in PERFECT tubes like this MATCHED PAIR! SYLVANIA 6SN7-GT 1950's MATCHED PAIR RARE COVETED FLAT-PLATES "139" 1951 DATE CODE! ..."More coveted and rare than the same tube with the more common T-Plates, these FLAT-RIBBED-BLACK-PLATES are worlds above in realism, depth, liquid-midrange, and a different kind of clarity, beautiful to observe but difficult to describe. It wasn't darker, grainier, undefined, or blurred, Like some T-Plates, but it was different in its luster and plasticity, much more realistic like your in the room with the band."..."...just like the recording engineer intended you to hear".... MAGNIFICENT SOUNDING "BLACK FLAT-PLATES" Dual Triode Perfect ELECTRICAL TUBES Sub-bass (10Hz - 60Hz) CHECKED & PASSED Mid-bass (80Hz - 200Hz) CHECKED & PASSED Midrange (200Hz - 3,000Hz) CHECKED & PASSED High-frequencies (3,000Hz on up) CHECKED & PASSED TESTS tube 1: 2,700 / 2,600 (102%/100%) MATCHED SIDES tube 2: 2,600 / 2,600 (100%/100%) MATCHED SIDES TUBE IS ALREADY PRE-TESTED, EXPERTLY MATCHED, BURNED-IN AND GUARANTEED! Recommended for: - Mikhail Rotenberg’s Singlepower Audio massive SDS XLR amplifier. - Atma-Sphere P1 - Cary Audio SLP 05 - Grant Fidelity (Yaqin) B-283 mkII tube buffer - Valvet Audio preamp - Singlepower PPX3-SLAM - Aesthetix Calypso - CJ MV55 - Cary SLP-05 preamp - CAD 300SEI - Yaqin MS-34C - Modwright Sony 5400ES - Oppo/Modwright BDP-95 - VAC Renaissance 30/30 MKIII - Bottlehead Crack AUDIOPHILE AUDIO TUBES WITH EXCELLENT VACUUM AND TEST RESULTS MUSEUM-CERTIFIED AMPLITREX TESTED! BID ONE (1) FOR THE MATCHED PAIR! BEAUTIFUL LIQUID-MIDRANGE SONIC HOLOGRAPHY …"Best described as having a euphonic sonic signature... Pervasive tube warmth that blankets the midrange irrespective of the program material falls in this category, and has proven to be a siren call for many 6SN7-GT tube-o-philes. Overly liquefying harmonic textures make these tubes a real keeper"….. Superior designed for critical industrial applications where 10,000 hour life, close triode section balance, rigid construction and stability are required. 6SN7-GT BLACK-PLATES were also labelled and synonymous to VT-231 Low-Noise Tested Microphonic Free No H-to-K Leakage (Heater-to-Cathode) No leaks (0) zero! Actual tubes were tested on the State-of-the-Art AMPLITREX AT-1000 Electron Tube Test System CERTIFIED ULTRA-LOW-NOISE MUSEUM SPECIMENS TubeMuseum tested tubes takes the guesswork out of the process of selection delivering you the best Audio tubes that there possibly can be. Terms of Auction BID 1 FOR 2 TUBES ( MATCHED PAIR) International Buyers - Please note: Import duties, taxes, and charges are not included in the item price or shipping cost. These charges are the buyer's responsibility. Please check with your country's customs office to determine what these additional costs will be prior to bidding or buying. We do not guarantee that your tester, or your tester's measurements will be the same as the Amplitrex AT-1000. Older testers, different testers, or the same tester may report different test measurements, and may not measure the same tube meaningfully (due to current dependency), accurately (due to calibration difficulties) or consistently (due to internal circuit drift) There is no warranty or returns based on what any other tube tester reports. THE COST OF ALL USA SHIPPING INCLUDES INSURANCE, TRACKING NUMBER AND DELIVERY CONFIRMATION NOTICE: All text & images © 2002-2024 Copyright © of The Tube Museum New York © All Rights Reserved By entering this site you are agreeing to be bound by the terms of this agreement. All photographs and text appearing in the Tube Museum New York (TubeMuseumUSA) site(s) are the exclusive property of The Tube Museum New York © (except where stated otherwise) and are protected under international copyright laws and treaties. They are made available for your personal viewing enjoyment only. No images or unique text are within the Public Domain. The photographs and text may not be copied, reproduced, redistributed, manipulated, projected, used, or altered in any way without the prior express written permission of The Tube Museum New York ©. The unauthorized reproduction or distribution of a copyrighted work, pictures, and text is illegal. 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