Hello all. I have been lurking around the board for about two years now, but never had anything to contribute witch is why this is my first post/thread. I have encountered however a problem with wich I cannot deal myself. I have been doing a lot of online searching and nothing sprang up. I have decided to build a Tillman F-fet preamp for my bass and swap the tone boost with the preamp. Everything turned out great, the bass sounded awesome and I was very happy. This is the freaky part. After installing the preamp I tested it and it worked. After that I played for half the night and everything was great - not a single problem. I packed the bass into a gig bag in the morning, took it with me to another city, never took the bass out for a week, came back with it and plugged it in to the same amp I was playing when testing. This time the bass sounded weird. I am now un-happy. I'm not sure it's the grounding because touching the strings and bridge does not change the buzzing. It almost seems as if the pickups are overly sensitive because if I touch the A and E strings veeery lightly the buzz starts. As if the slightest vibration of the strings is being picked-up. Also the signal is about half as loud as it was. I have tried it on a decaying battery, on a new battery (both measured), without the whole pre-amp, with a new pot and without the pot (signal and bridge/ground straight into jack). The only time the bass acted o.k.was with the 'no-pot' option. The moment I solder the bridge/ground onto the pot, from the pot a wire into the jack - buzz. No difference at all with or without the pre-amp. Only thing is that with the pre-amp and no battery there is almost no sound at all witch is as should be. There is also this : since this buzz thing started there is this soft popping sound when the pot goes all the way up or down. I now have no idea what could of happened and decided to seek (& destroy) help. If any one here has any ideas at all please help me out. I live in Poland so if do not reply right away it might be because of the time difference. Thanks and cheers !