Bugera 333xl Mystery

[matt mincer]

Hey Folks,

Is anyone familiar with these amps? I was brought one by the local School Of Rock. They told me it had been fixed several times, it wasn't working and had been sitting around for a year. Seriously, that's all the info I got from them. I replaced the main fuse and it seems to be fine. The only other problem I have found a crackling from the speakers when I shut it off. Is also does it if I turn it back on quickly, ie, tubes are still warm. It seems to be related to a relay. Anyway, at the risk of asking a loaded question, does anyone know what to look for in an amp that's working? I'm going to let it cook overnight but other than that?

Thanks
Matt

[PRR]

In a school, a blown fuse may be an insolvable problem.

But why did it blow? Could be just old age, or physical abuse.

_I_ would rock-out like a teenager, trying to invoke some problem that only happens when working HARD. (Oh gawd, 120 Watts.) It may be polite to own a large dummy-load with a monitor speaker on a fader, and an old iPod to keep the amp busy.

[matt mincer]

In a school, a blown fuse may be an insolvable problem.

But why did it blow? Could be just old age, or physical abuse.

_I_ would rock-out like a teenager, trying to invoke some problem that only happens when working HARD. (Oh gawd, 120 Watts.) It may be polite to own a large dummy-load with a monitor speaker on a fader, and an old iPod to keep the amp busy.

That was my thought too, I've almost never seen a fuse blow for no reason. I'll let my wife know I'm rockin' out for science!

Thanks
Matt

[kagliostro]

Schematics attached


Franco