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Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Solid State Amplifiers => The Newcomer's Forum => Topic started by: socal_southpaw on April 19, 2009, 04:07:30 PM

Title: Left my amp on, now its a giant warning buzzer.
Post by: socal_southpaw on April 19, 2009, 04:07:30 PM
I have a 85 watt Peavey Backstage amp which I dearly love, but have accidentally damaged.  Like an idiot, I left it on while I went on vacation for over two weeks.  I discovered what I had done one night when it woke me up by suddenly making an extremely loud, continuous buzzing noise.  Now that's all it does when switched on.  Obviously, something is fried from being left on so long, but I have no idea what it is, if I can fix it myself, or how expensive it will be to get fixed if I can't.  Can anyone give me an idea of what kind of damage I'm looking at so, at the very least, I don't get fleeced at the repair shop?  Any insight would be much appreciated.
Title: Re: Left my amp on, now its a giant warning buzzer.
Post by: Boprikov on April 20, 2009, 02:32:33 PM
Maybe there is a failed electrolytic capacitor at the power supply. Without capacitor regulation, DC ripple voltage makes the amp hum continuously. It should not cost a fortune to get fixed.
Title: Re: Left my amp on, now its a giant warning buzzer.
Post by: Enzo on April 20, 2009, 08:52:22 PM
I don't know if you can fix it yourself or not.  It will require soldering parts to the circuit board, I'll bet my lunch money.

Leaving it running is not going to hurt it.

Look closely at the cone of the speaker when you turn it on.  If the cone moves one direction and stays there, along with a loud hum, then your output stage is blown, and there is DC voltage on the speaker.   DOn;t leave that on.

If the speaker seems to stay at rest but hums loud, you may just need a filter cap resoldered.  or maybe replaced.

Byond that, it should not be complicated for e technician to repair.
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