Just purchased a Teal stripe with a scorpion for $40 from a pawn shop. I knew it had issues but for that price, I'll throw dice. The problem is that it has very low volume and a very muddy sound. I pulled the Scorpion and it sounds great in another amp. I put another speaker in it and I get the same issue. I cleaned the pots and jacks, even used a direct line in the effects loop. Still no change. Any thoughts on what to check next?