#1
Hello everybody,

I have problem with my Bugera. I bought it about a half year ago, and it worked without problems until now. I had the amp at my band's rehearsal place for about 5 months and last month it was very cold there (because of the wather, it's in a garage), about 0 °C.

Then I took it to my home, I played about an hour, then I turned off the stand-by, so it was just turned on. About half an hour after that, I heard a loud bang then the amp turned off. I've found out, that it was the fuse, but when I tried to plug it in on different places with another fuse, it happened again. I'm afraid that its a problem with amplifier.

Have you any ideas of what it could be? I also discovered, that while transporting, the impedance switch had been set to bad value, but I don't think it's the problem, because it wouldn't mess whole amp but just speakers.

I would appreciate every idea. Thank you in advance!
#2
contact bugera an use your waranty dude.

For future refrence, never leave your amp on standby that long if you can help it.
2002 PRS CE22
2013 G&L ASAT Deluxe
2009 Epiphone G-400 (SH-4)
Marshall JCM2000 DSL100
Krank 1980 Jr 20watt
Krank Rev 4x12 (eminence V12)
GFS Greenie/Digitech Bad Monkey
Morley Bad Horsie 2
MXR Smart Gate
#3
You may have blown your OT if it was set to 8ohms and needed to be on 16ohms. With ohms you can sometimes go up, but never down.
2002 PRS CE22
2013 G&L ASAT Deluxe
2009 Epiphone G-400 (SH-4)
Marshall JCM2000 DSL100
Krank 1980 Jr 20watt
Krank Rev 4x12 (eminence V12)
GFS Greenie/Digitech Bad Monkey
Morley Bad Horsie 2
MXR Smart Gate
#4
what was the impedance setting it was moved to, and what is the impedance on the cab? Incorrect impedance setting can, and will damage your amp, not just speakers. If the impedance on the head is LOWER than the cabinet, you should be OK.

IE: 4 ohms on the head going into an 8 or 16 ohm cab.

If the impedance switch got bumped to 16ohms and your cab is 8 ohms... you may have smoked your output transformer.

Leaving an amp on standby doesn't hurt it. It just leaves the tube heaters on, so you may reduce the life span of your tubes a bit, but it shouldn't really be any worse than if you had
played it for the same amount of time.

The loud bang is what concerns me here. Did it make the noise again when you replaced the fuse? I'd stop putting fuses in it until you figure out what is wrong. Do any of the tubes look burnt? If so , try replacing them and put a new fuse in it. If it blows again, take it to a tech. Actually, I'd just take it to a tech now. If it has blown two fuses already, there's definitely a problem.

You said you've had it 6 months... did you buy new? Still under warranty?
Quote by tubetime86
He's obviously pretty young, and I'd guess he's being raised by wolves, or at least humans with the intellectual capacity and compassion of wolves.


You finally made it home, draped in the flag that you fell for.
And so it goes
#5
Quote by jpatan
what was the impedance setting it was moved to, and what is the impedance on the cab? Incorrect impedance setting can, and will damage your amp, not just speakers. If the impedance on the head is LOWER than the cabinet, you should be OK.

IE: 4 ohms on the head going into an 8 or 16 ohm cab.

If the impedance switch got bumped to 16ohms and your cab is 8 ohms... you may have smoked your output transformer.

Leaving an amp on standby doesn't hurt it. It just leaves the tube heaters on, so you may reduce the life span of your tubes a bit, but it shouldn't really be any worse than if you had
played it for the same amount of time.

The loud bang is what concerns me here. Did it make the noise again when you replaced the fuse? I'd stop putting fuses in it until you figure out what is wrong. Do any of the tubes look burnt? If so , try replacing them and put a new fuse in it. If it blows again, take it to a tech. Actually, I'd just take it to a tech now. If it has blown two fuses already, there's definitely a problem.

You said you've had it 6 months... did you buy new? Still under warranty?



Well there are 2 8 Ohm speakers, so the impedance has to be set on 4 Ohms and while I was transporting it in the car, it switched to 8 Ohms.

By the way, it burnt 4 fuses, always with loud bang. I tried also reseting the impedance, but nothing has changed.

Also I checked tubes, and I'm not sure. The glass ones are ok, but the others are coated by steel, so I'm not sure if I can see whether it is burnt or not.

So you think there is no way I can fix it by myself? :-/
#6
Quote by LordAddy
Well there are 2 8 Ohm speakers, so the impedance has to be set on 4 Ohms and while I was transporting it in the car, it switched to 8 Ohms.

By the way, it burnt 4 fuses, always with loud bang. I tried also reseting the impedance, but nothing has changed.

Also I checked tubes, and I'm not sure. The glass ones are ok, but the others are coated by steel, so I'm not sure if I can see whether it is burnt or not.

So you think there is no way I can fix it by myself? :-/

not unless you have good electical skills with complex circutry
2002 PRS CE22
2013 G&L ASAT Deluxe
2009 Epiphone G-400 (SH-4)
Marshall JCM2000 DSL100
Krank 1980 Jr 20watt
Krank Rev 4x12 (eminence V12)
GFS Greenie/Digitech Bad Monkey
Morley Bad Horsie 2
MXR Smart Gate
#7
The metal things are just covers for the preamp tubes. They can be removed to check them. But if your head was set at 8 ohms running a 4 ohm load... be prepared for the worst. Especially if you had it running a solid hour and a half like that. Probably not good. Take it to a tech.

EDIT: If your speakers are wired in series you'd be ok. If they're parallel wired, then you're probably screwed.

Series wired would be a 16 ohm load, which is ok for an 8 ohm supply.
Quote by tubetime86
He's obviously pretty young, and I'd guess he's being raised by wolves, or at least humans with the intellectual capacity and compassion of wolves.


You finally made it home, draped in the flag that you fell for.
And so it goes
Last edited by jpatan at Dec 11, 2011,