Hi there,
My acoustic duo partner's guitar has developed an odd problem that I can't find an answer for anywhere. He has an old Fender acoustic with an LR Baggs Active Element pickup installed and lately it has been going up and down in volume when playing - one song it's at normal levels, the next is noticeably lower in volume. Usually he has to turn down a good bit because that pickup is pretty hot, so to speak; but when the level drops turning the volume knob up to the top makes no difference. And yes the battery has been changed - just hours before a gig and it still was out of whack.

We have eliminated any chance that it was PA related - plugged him into every channel on the mixer and still the same results, also changed cords. Any suggestions? Thanks!!