Hey. OK, recently I've been fiddling with my amp settings a lot - comparing sounds between cutting instead of boosting, playing flat etc. I have a Trace GP12SMX AH250 and a Trace 2x10 8 ohm. I managed to find a sound that sounded alright when the graphic EQ was cut instead of my usual "seagul" of boosting. However, I decided I liked it more meaty and changed back to the seagul-look. It's been really, really quiet - no matter what settings I use. I'm certain it's the amp, becuase this doesn't seem like a cab issue - I guess maybe my tweeter in the cab is buggered? I have it set at 11 oclock on the attenuater. Cables work with my PA and instrument cable works perfectly when I plug straight into my PC. My "gig" volume is usually 3/4 on the input and 4/5 on the output. In the house the loudest I could go would be 2/3 - after that the house start shaking, and things break. Right now, however, I'm at 5/5(!!) and thats close to the max "house" volume! Ever since I got my amp, there has been a dodgy preshape switch - so this could be anything from a capacitor or resister in that part of the circuitery - however, after having a "warm up" time, the amp has performed perfectly. My initial thoughts are that a tube, or both are dying. My amp is an early 90's model and I have no clue as when the tubes were last replaced. i've tried turning the blend knob to 100% SS, yet the volume issue still occurs, which led me to think that this is related to a power section. Thoughts? I'm pretty bummed. I have a gig in 2 weeks, and we were going to use my amp. I don't trust many music shops/know very little of amp tech's reputations in my area, so I'm hoping I can learn from this... please help..