Craig was very proud of his rack-mount tube-powered bass amp. But there were crackles and pops while playing. He wanted to have everything looked-at. Could The Unbrokenstring Crew get it tuned up?
This is a heavy monster. Yes, that implies 400 watts out.
The sockets are in good shape, but just need some chemical attention. You can still get pipe cleaners, but instead of checking the tobacco aisle, you might look at the gun cleaning supplies section of WalMart to find them.
The push pull class AB1 pairs are oriented from front to back in the chassis. Once the operating point was established, pairs of tubes were sorted that had similar characteristics. So we matched six pairs of tubes to within 2% of each other. Power and output transformers are seen in the foreground.
Thanks for reading all the way to the end!
CONTACT – David Latchaw EE