All tubes are tested on a professionally calibrated Triplett 3444.
National 6DJ8 (Made by Matsushita) - 1960s - Vintage Tube Services Red Tip - $55/pair Free Shipping These tubes were purchased from Andy Bouwman at Vintage Tube Services. Andy tests for microphonics and then grades the tubes on a color system. Red (the color of the paint on these tubes) signifies low microphonic, suitable for Line Level tubes. Tube #1: 12ma @ 10,750gm and 15ma @ 11,000gm Tube #2 13ma @ 10,500gm and 13ma @ 10,5000gm = 90/97%
Date Code 64-48 = 1964 48th week No Microphonics. No Gas. No Shorts.
13,000gm is the standard for a new 6DJ8, and 8400gm is the replace number on a Triplett 3444.
5 Day Return Policy - I endeavor to thoroughly test your tubes before shipment to ensure that I represent them accurately. If they do not perform as expected in your system - microphonics or noise for example, then you may return them for a full refund. Buyer pays return insured shipping. The 5 Day Return is not intended to provide a Buy-Try-And-Return method by which a Buyer can "tube roll" and return them if they do not produce a subjectively pleasing result.
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