SWR workingman's 12 troubleshooting
Hi guys, I'm new to these forums and wondering if anyone can give me a little help diagnosing a problem with a used amp I just purchased. It's one of the older generation of SWR workingmans 12 amps, and everything sounds fine until it's been on for 10 or 15 minutes -- then I start hearing loud static/scratchy type sounds through the speaker. I guess I need to bite the bullet and find an amp repair guy to diagnose it, but just wondering if this is enough info to point me to a particular problem? Transformer maybe? Thanks a lot for any advice/info!