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Hello Folks: I have a mystery on my hands. Hopefully, someone has experienced this before and can share thoughts or suggestions. My homebrew tube amp runs great for about 10 or 15 minutes then it just turns off. The 6 volt pilot light, tube filaments, and 5 volt rectifier GZ34 turn off. Maybe 10 or 20 seconds later, everything powers back on again. The filaments, pilot light, and rectifier tube all come back on as though nothing happened. This same situation has occurred twice. I typically turn the amp off pretty soon after it comes back on again since I'm not sure of what is going on. The power transformer and resistors in the circuit are barely warm at the time when it turns off. I am not seeing any smoke or smelling anything burnt. For this circuit, I am using a Hammond 270FX power transformer, 3 amp slo-blo line fuse, four EL84s, one ECC83, one EF86 preamp tube and a GZ34 full wave rectifier tube. The circuit is very similar to an early 1960's British 30 watt amp. Thanks.
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Have you tried plugging something of similar power requirements into that outlet? It's not a common problem and only a couple of possibilities come to mind. One is an intermittant fault or short on the primary side AC wiring and the other would be if the PT has some kind of thermal protection that is tripping incorrectly."Take two placebos, works twice as well." Enzo
"Now get off my lawn with your silicooties and boom-chucka speakers and computers masquerading as amplifiers" Justin Thomas
"If you're not interested in opinions and the experience of others, why even start a thread?
You can't just expect consent." Helmholtz -
If it has a reverb, turn that down. Next time the amp goes away, ball up your fist and whack the top of the amp hard. Did that wake it up? DO anything? And while it is working, whack it. Does that cause any crackles or noises? Or indeed does that trigger a dark spell? All that is to expose loose connections in the amp.
Purists would use a rubber mallet, I just use my fist.Education is what you're left with after you have forgotten what you have learned.Comment
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Thanks for the advice. Just started troubleshooting and switched outlets that I was using. I think this may have solved the problem. The amp was originally plugged into a power strip that was connected to another strip finally plugged into the AC mains outlet. Bad AC power seems like it could have been the problem. Does anyone have experience with Furman or APC power conditioners? Maybe one of their outlet strips would be better for my guitar rig set up.Comment
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