Hey guys, Long time listener, first time caller, and I really need some help. Here's the problem: I have a Warmoth Jazz bass that I bought used, and it has been awesome until recently. It has Seymore Duncan SJB-2 pickups and an older Audere JZ preamp (from the first couple of years they were building them). The trouble is that I plug the bass in, and can play it in all its glory for about 30 seconds-a few minutes before something happens and the power output suddenly cuts significantly, and it seems that the tone loses some of its definition. It doesn't always seem to take the same amount of time, but it always happens. It will happen even if plugged in and left laid flat on a table and not touched (with volume on bass and gain on amp turned up high so I can hear what's going on). To try to fix this I have: 1. Replaced the battery 2. Replaced the input jack 3. Replaced the wires from the battery box (It seemed that there was a bad connection there somewhere, with some of the wire a bit worn and stressed from where the battery box opened and closed [a problem with some of the flip-out types]. Also, that wire had been joined in several separate sections - leads from various components to wires connecting to leads from other components - so I thought to cut some of that out.) 4. Foil-shielded the cavity while I was in there, just for good measure. I did this with aluminum tape, connected the cavities with wire, and a wire to the bridge for ground (where the other ground wire is). It was a bit noisy, and from the few moments of good playing time I get it seems to help that issue. 5. Gently stroked its headstock and told it sweetly that it was my favorite, and that those two new P-basses I just got were nothing to be jealous of, and that it was the one I wanted to play at my gig on Friday. Is there still some kind of power issue from the battery to the preamp? I'm pretty sure my soldering is good (not 100%, but the joints look OK, and it does make noise). Is there some kind of grounding problem, and if so, how do find/test it? Is my preamp fried? Could it be an issue with the pickups? Thanks!