I bought a used AC30, my first tube amp, that's spent a good 12 hours the past two days maxed out on the top boost volume without issues and as such I'm not too concerned about what happened earlier but wanted to ask. It's first worth mentioning the reverb tank needs to be replaced and the tubes MIGHT be old and in need of replacement - the guy I bought it from ($600) said he got it off EBay as an open box and had it for about a year. I need to move a few hundred miles in a few months so I'll wait until then to do it....

With that said, I plugged the EVH 5150 Overdrive in today and was playing with it. The pedal has a boost (no idea the DB) and when I maxed out the gain, output, and hit the boost the amp sounded like it shorted out. The on/standby lights were still on but the sound "squeeled" out very quickly and power cycling the amp APPEARED to be the only solution as turning the pedal on and off had no effect. I didn't want to screw around with it enough to get a real diagnosis and as the amp had been and still is fine just took the pedal out of the chain and left it alone.

Any thoughts? I wouldn't imagine a pedal could cause damage to an amp like that.
First tube amp...

-play it 12 hours maxed out
-hit it with a maxed out boost
-disregard failure and diagnosis

Yes, your actions qualify as "weird behavior after buying used".
Quote by reverb66
I'm pretty sure the Bible requires that you play through a tube amp in Texas.
I would guess it is possible the tubes just gave up. AC30's run pretty hot, it is possible a component (whether a tube or not) failed at the intense heat. The stock tubes are not much to shake a stick at. Replacing them is smart. However, if you are trying to get metal-levels of gain out of an AC30, I'd suggest you have the wrong amp.
Last edited by Will Lane at Apr 19, 2017,