: Had a friend give me the head to a Sunn 200S bass amp about 8 years ago. He used it as a PA system for his singing. Something happened to the circuit and the rectifier(GZ34) started to glow red. After he gave it to me, I replaced the tube but that didnt't seem to fix the problem. Kept it for a long time and almost gave it away to Goodwill but couldn't quite do it. Just bought a digital piano and I've heard that these bass amps were pretty good. Anybody familiar with this one?? Hopefully it should't be too hard to fix.
Stormin;
If you mean the plates inside the rectifier were glowing cherry red, then the amp is pulling excessive current. Could be shorted filter caps, shorted output tubes or possibly a short in the output transformer. Odd that the fuse or circuit breaker didn't blow if the amp was pulling excessive current. Anyway, it's a job for an amp tech. Filter caps and output tubes aren't too expensive, but transformers are! Don't give it to Goodwill whatever you do. Heck, I'll even buy it from you as-is if you don't want to spend the bucks to repair it!
Good Luck!
Ryan
