I have read many satisfied customer reports for the Behringer ACX1800 amp. The most common complaint seems to be the weight and the wiggly knobs which attach to the potentiometer shafts. The weight I can live with but the wiggly knobs do seem rather a potential problem since they are attached to pots which are soldered to the circuit board. Every wiggle stresses the solder connection by moving the pot. There are three simple solutions to the problem. The first two, the factory should make the shaft holes in the bezel smaller or the knob's shaft diameter a little bigger. That eliminates the wiggle room and removes the side to side stress on the pot. The 3rd solution, which I used is to wrap the knob shafts with 4 or 5 turns of that green 1/4 inch painter's masking tape, thereby taking up the slack which allowed the shafts to move sideways and up and down. Doing so made my knobs have the feel of the knobs on an expensive piece of lab equipment. Literally no movement of the potentiometers shaft as I set sounds I want.