I've been doing my best to learn as much as I can lately on the world of bass pups and how they apply to me. I'm playing in a band right now(metal) and we're tuned low A,D,G,C. I was using my 4str Tobias Growler that I've had and loved for years. When I joined this project, I had my bass set up with 130 ga. strings, and it played great. I then went out and bought a new 400+ head, a new 6x10 and a used 1x18. Hooked it up, pluged in and..... FART! Yery loud farting on any lower freq's. I couldn't figure out what it was, I tried everything(inputs, ohms, etc). I had to have a new nut made so while it was in, I had them "bench test" the electronics and everything came out fine. The pup height was set to spec and the bass played great except for anything loud. It was in my uneducated, but not inexperienced oppinion that I could have all the e.q. and volume on the bass turned up and nothing should be breaking up. I then tried some passive basses through the rig. Viola. So I ended up buying a used MIA P-bass and plan to go with so SD 1/4's and call it a day. Now here's my question, the growler has the MM4 Bart; what pre-amp is used, and is this noise caused by the signal being to hot. The guy who set up my P-bass, said an 18volt pre-amp sends about 17-18db of gain, where as a factory passive is about 6, and the SD's will be about 8-9. *** does this mean? Is that the distortion I hear? Is My growler useless in this band? Any personal experience and detailed and what may even seem basic info will be making me happy.