Hi all. I own a Peavey TNT 115S bass combo amp, which I bought new in late '99. It has always been very reliable, even though it's taken its share of abuse, being transported, etc. I have begun to notice recently that it seems to be making farty, distorting sounds. This is especially noticable when playing lower notes. It still powers on fine, and volume, gain, etc. all seem to work fine. I think it seems to be vibrating quite a bit as well. I keep it over at our guitarist's place, and always had his smaller Fender bass amp on top of mine (as a backup). Last practice, the Fender amp was actually _moving_ on top of my amp (and I wasn't playing any louder than normal). I also noticed at the last show we did, my picks, earplug case, and small tuner that I always put on top of the amp all ended up falling off. Someone suggested that a screw may have come loose from the speaker's surround? I haven't had the chance to look at the amp yet (it is over at our guitarist's place, since I don't really have room for it at our apartment). Anyone have any thoughts before I try to remove the grill cover and look at things? Thanks in advance...I really want to get this amp sounding good again, like I know it can. I know this is a fairly popular model, so if any of you own this amp or have used it, I would appreciate any tips.