I have been going insane with this problem myself. For me, its not just when I use my overdrive, its when I get an obscenely awesome tone. It'll pound for 30 sec and the s*%! the bed. Lemme know any info you get because I am going to attempt to cram this up an unlucky salesmans hoop on monday. I noticed on the back that this has a 20amp breaker on it and I think that this amp might be pulling more that 15amp when overdive or tons of bass is applied. It seems like its "browning out" to me, more pull than service to the amp. I want to try this with a 20 amp service but haven't been able to yet. It is clearly going into some kind of protect mode because I have to stop for 1 one thousand...2 one thousand...3 one thousand... before it'll kick back in. If I try to play through it wont kick back on, that tells me its about to melt. This has happened to me on a ton of shows, practices, with different basses, different bass players, venues, setups, ect. I checked the tubes, no rattle or discoloration. Everything inside looks pimp. I've blown breakers in countless bars with this amp.
ANY HELP ANYONE CAN GIVE WILL BE AMAZING!
I can't just turn this amp down anymore, it sounds so good when you push it a little, and then unfortunatley makes me look like a dork 15 sec later for about 3. I thought I was crazy and I just turned it down, unacceptable. I bought awesome gear and I want it to work like it should.....awesome. Today was a pinicale for me: I brought in a friend to help me with bass tones (we're doin pre prod) and he started tweaking. As soon as he got a crazy thick crunch tone..you guessed it. He said, "Thats weird, my big block 750 doesn't do that, its gotta be a defect." If I turn up the tone I have picked for myself up a little too much same thing. I've tried it with multiple speaker config's all correct ohmages of course. Another friend suggested overheating, I noticed the whole amp only has one fan blowing in. I do have the non rackmount version, had to pull it out tonight to check tubes and will try without enclosure. Might attempt some fancy fan work. Never thought I'd only have one fan....
HELP!
NATE