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I built a Boogie Mark I clone in 1995. It had lots of gain on tap and I actually put a 5751 in the V1 position to tame it a little. I sold this amp to a friend about 8 years ago. Recently it started blowing fuses and he asked me to take a look. I traced it to a bad filter cap right off the rectifiers before the standby switch. Looked fine but tested dead short. There are three 22uf caps in parallel (66uf). They were Illinois caps. Only one was bad, but I replaced all three as a precaution. Powered it up and everything seems to be working. Checked voltages, bias, the usual stuff.
When I started playing through it, it sounded okay. The high gain channel sounded high gain, normal channel sound clean. But when I turned up the master volume, there was very little power there. Sounded more like a 10 watt amp when I dimed it. I replaced all the tubes with known good ones just make sure, still very weak. It's using 6L6s biased about 65% at idle.
Is it possible that the output transformer might be the culprit? Damaged but still semi functional? My friend is in a punk band and told me he likes to play with everything on 10. He does this with most amps he plays (I guess there are venues you can still do this?). So I know the amp is getting a workout. But, it doesn't display any odd, ugly sounds. Just very low volume for what I know was a loud ass amp years ago. I got the power and output transformers from Hoffman Amps back in 1994. The same ones he used in his amps before he quit building amps.
I have not done the basic trouble shooting for an output transformer yet. Ran out of time. I'll get a chance next week to take a second look. I've only blown one output tranny and that was on a single ended amp. I turned it on and got hum and no sound. So I don't have much experience with bad output transformers. Any thoughts would be appreciated.
When I started playing through it, it sounded okay. The high gain channel sounded high gain, normal channel sound clean. But when I turned up the master volume, there was very little power there. Sounded more like a 10 watt amp when I dimed it. I replaced all the tubes with known good ones just make sure, still very weak. It's using 6L6s biased about 65% at idle.
Is it possible that the output transformer might be the culprit? Damaged but still semi functional? My friend is in a punk band and told me he likes to play with everything on 10. He does this with most amps he plays (I guess there are venues you can still do this?). So I know the amp is getting a workout. But, it doesn't display any odd, ugly sounds. Just very low volume for what I know was a loud ass amp years ago. I got the power and output transformers from Hoffman Amps back in 1994. The same ones he used in his amps before he quit building amps.
I have not done the basic trouble shooting for an output transformer yet. Ran out of time. I'll get a chance next week to take a second look. I've only blown one output tranny and that was on a single ended amp. I turned it on and got hum and no sound. So I don't have much experience with bad output transformers. Any thoughts would be appreciated.
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