I have a G&L L2500 USA that has developed a problem in active mode. No problems in passive mode, but in active mode I've lost volume and if I hit a note hard, the preamp seems to "fart out". There is some volume happening just very little. I put in several new batteries with no improvement. A few months ago, the bass started giving a mild "pop" in active mode when I touched the strings, as if there might be a grounding problem, but it wasn't noticeable enough to bother anyone else, and I didn't really care, so I just let it go. Active mode still worked normally at that time. So maybe my grounding problem is worse? Anyway, now in active mode I just have very low output and some hiss etc. Passive mode is normal, for now I"ve just taken out the battery and it works fine at gigs etc. I've taken the bridge off before and "re-grounded" the bass, so that's no big deal but I thought I would check here first before I tried that again. Thanks for any ideas.