Just purchased a used, solid state MG15fx amp that produces very little sound ... not much louder than talking at full volume. And the sound quality is very poor, cloudy-like, much like a radio station that is a little off channel. Played my MP3 player through the MP3 jack and it sounds the same - poor. Likewise, the sound out of the headphone jack is just as poor. What is so strange is that the quality of the sound is good for the first 4 to 5 seconds, then things go downhill fast. Turn off the amp and turn it back on right away and I can repeat the process from good to bad. Not sure where to begin? Power source/transformer? Capacitors? It terms of appearance, the thing looks brand new.