Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: matt mincer on March 17, 2018, 05:01:00 pm

Title: Bugera 333xl Mystery
Post by: matt mincer on March 17, 2018, 05:01:00 pm
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
Title: Re: Bugera 333xl Mystery
Post by: PRR on March 17, 2018, 07:41:16 pm
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.
Title: Re: Bugera 333xl Mystery
Post by: matt mincer on March 17, 2018, 08:44:27 pm
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! :laugh:

Thanks
Matt
Title: Re: Bugera 333xl Mystery
Post by: kagliostro on March 18, 2018, 06:55:15 am
Schematics attached


Franco