K so I have this Peavey XXL. Lately It's been extremely quiet. However, if i mess with the effects volume button for the fx loop, theres one point that drastically increases the volume.
What could the problem be?
Something similar happened to me. But it was with the channel selector switch. It would get really quite, then if i moved the switch around a bit, it went back to normal volume. Right now it's getting repaired. I think it might just be a loose wire or something. I can tell you what the problem is when i get it back.
The FX volume button is functioning as an attenuator. Just keep it at all full volume. If it continues to die out though Peavey amps are known for getting their effects loops dirty so spray some contact cleaner on a 1/4" cable and just stick it in and out of both the send and return a few times, wait a few minutes for it to dry, then jam away.
Same thing happened to my XXL. When the 10db effects loop cut button is half-in, its full volume; otherwise, it is 10db or so quieter. Year before, it would get louder or quieter randomly, but now its always quieter. It still has a ton of volume on tap so it doesnt matter, i just raise my master to 2 instead of 1. It could be a loose wire or the effects loop being dirty, mostly the former.

R74NOGRADY, i'll wait for what happens to your amp, and how much it cost, since i need to find a place that will work with solid state amps.
Modded Steinberger Spirit (white) (SD-AH/EMG Select)
Modded Steinberger GP-2R (white) (EMG81/60)
Peavey XXL head
Hughes and Kettner Cream Machine
Hughes and Kettner Blues Master
I got my amp back this week. It's a beast now
The guy cleaned all of the pots and replaced a couple of stripped screws. When i read the next part of the receipt, i nearly shit my pants... He fixed 180 solder joints!!!!
He told me that the previous owner must have dropped it or something. I'm glad i got it fixed. No more problems. He charged me 155$ for the job.
Wow lol
well it doesn't fade in and out like it used to and if i raise the level on my fish n chips a little bit it kinda makes up for it. I'll just have to deal with it until i can afford to look into getting it repaired.