Ok the skinny of ot is I was using this amp as my main practice amp for the past 4 months since new. The other day I was practicing and the volume dropped and came back and dropped. tried different leads, my strat may L.P. etc and to no avail. For the hell of it tried it again yesterday and it sounded like it had a very bad tremolo circuit-which this amp does not, reverb made no difference. Monoprice not offering any help on this issue and then sends me a robot "how did we do" email. Anyways what could be the problem with this amp? I have never ran into this before and wondering if it is a tube issue or something else?