GtrGeorge! said:
nah..it hums wherever I take it.
I used it 3 days ago at a rehearsal (my rack gear is troubled right now)..and it was plenty loud but....still a hum was ever present. My tube gear is less noisy..and that is saying something.
first off, are your audio cables near an outlet? you can get massive hum if they are too close and your cable is not shielded properly.
is the ground where you live or where your currently plugged into okay?
check the grounding on the amp cord the trace it to the internal for a look if/when you look inside.
try blowing the pots out with some canned air from a computer store. then if that didn't help
try taking apart the unit, but start very slow with just the cover plate. i have never used this particular unit but most rack equipment has a top cover plate for ease or access during the build as they are typically assembled then put in the rack unit case then to a rack holding case during use.
as you do this, use the canned air but just bend the hose down a bit and point it around rather then tip the can and freeze all your internal parts for no good reason
i have done this, generally never hurts anything but never a great idea.
then put the unit back together and try again. if then a hum still continues, take the top off again. now this time look around to see if any random piece of "something' might be causing a small short or bridge. maybe a connection has come distant but not completely apart enough to short but just damage the sound quality.
maybe a capacitor is going or a fuse is on it's last leg. check the fuse for sure... lol.
try these things and get back to me.
good luck