I have a buddy who has an AC30 and he just had the inputs literally melt together. I had never seen that on an amp and thought it might be something that is a sign of a much bigger problem. A coworker of my wife's just offered to sell me his AC30 and given what I've seen my buddy go through, I'm a bit apprehensive. Anyone have any info on what the most common problems are and the relative cost to fix them? I love how the amps sound, but would rather spend the extra money on something that will work instead of paying a repair shop over and over...