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VT-231 tube hum
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Posted on January 6, 2017 at 11:20:05 | ||
Posts: 979
Location: Russia Joined: July 1, 2010 |
I installed a pair of Sylvania 6SN7GT/VT-231 tubes in my amp. The tubes were purchased as NOS from a reputable dealer several years ago. One of the tubes instantaneously produced a very loud low frequency hum, which means that it is faulty. I wonder what could be the reason for such failure, if the tube was kept in a drawer for several years. The same thing happened earlier with one of JAN GE 6550 tubes and one of Siemens/RCA 6922 tubes. |
Just out of curiosity, posted on January 6, 2017 at 17:42:33 | |
Did you ever play with the global negative feedback in this amp? |
Dunno about that, posted on January 7, 2017 at 00:57:15 | |
I can't remember any which have lost vacuum sitting in storage. |
RE: Dunno about that, posted on January 7, 2017 at 05:52:59 | |
Posts: 1465
Location: USA Joined: August 8, 2014 |
Likely a cathode to filament short. |