In Reply to: Stromberg AP-55 question posted by gkargreen on March 9, 2010 at 10:22:46:
I restored a pair of Stromberg Carlson APH-50's with completely new PSU caps, signal caps, a few old resistors and new tubes.... the same 120 Hz hum is present.
The only way I was able to reduce the hum was ny using Vintage 5U4G rectifiers vs. the Sovtek's. But the hum is still audible from 2 feet away. As long as the music is loud it doesn't affect me, it's between songs that the 120Hz bothers. I guess I have learned to live with the imperfections and listen through them.
As far as the speaker connections are concerned, I jumpered the relay connector board direct to the 8 Ohm and Ground connection on the Octal Output Socket.
I would assume that the safet place for the ground is the DC Ground and not the Chassis ground, but you can experiment with both and see which works best.
Often with equipment of this vintage, the Chassis and DC ground are the same.
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Follow Ups
- RE: Stromberg AP-55 question - shermanr@prw.net 14:06:01 08/25/10 (0)