I have a Peavey Ultra 112 that has recently started to act up on me. Its still sounding great, tone wise, but when I hit say a Ab on the top string, I get this kind of buzz in the background. Its really noticeable. It seems to only happen when I really dig into a note, or hit a hard bass note. Its also amplified when I have my TC alter ego x4 running, particularly on a fast Lesley setting. The volume will also drop from time to time. My first thought was a bad power tube, but I switched them out for a spare set I have, and it didn't seem to help at all. I also tried hooking it up to a speaker cab, just to see, and the buzzing didn't seem as bad, but was still there.

This first happened when I was jamming at a friends house the other night. I fooled with it for a bit then, with not luck. We tried jamming and song, and about half way through, the amp started to make a horrendous scream that wouldn't stop until I hit the standby switch. The amp has always been a solid workhorse of mine, with no prior issues. I'm just wondering if anyone here may have experienced something like this before, and maybe to help me out.



I've narrowed it down to a faulty preamp tube in V1. I tired tapping it with a pencil, and could hear a thud come through the amp pretty good. I tried 2 different 12ax7's I have on hand, and all 3 are acting the same. Does this mean I have a bad tube socket?
PRS Custom 24
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Peavey Ultra 112
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Last edited by red.guitar at Nov 18, 2016,