I did a gig last week and had a major problem with a lack of volume which I put down to a problem with my rig. I had to turn my LMIII up to the max to get a reasonable level in the 5 piece band I play in which is ridiculous. Normally the gain and master are at 12 o clock. Anyway, when I got home I plugged my bass into my practice rig and it was really quiet. I put a new battery in and it made no difference so I switched it over to passive and still it was very quiet. I started twiddling all the pots and flicking switches and everything worked ok but when I rotated my pickup pan knob there was a click and then the volume back went up. I thought I'd fixed it but there's still a drop in volume and the tone seems a bit hollow / brighter. The bass has 3 humbucking pups and they all work. I realise I'll probably have to find a tech to get it fixed but does anyone have an ideas what the problem could be?