OK... I can't find anything with quite the same problem when I search, so here goes. Just replaced my strings on my Jazz for the first time, and they're all fine apart from the E string... it's making a noise that (to me) sounds like a string is vibrating inside the string... hard to explain. I'm talking about plucking the E when it's not plugged into an amp. It's more noticable when the string is open - in fact, it's really annoying. When I do plug it into an amp it vibrates my cab something rotten. When I fret it, it almost goes away, but you can still hear it if you listen carefully. I took my bass into the shop and the guy played about with it for a bit, adjusted the truss rob, played with the bridge, nut etc... it kinda died down very slightly, but not enough to be happy with! It's come back with avengance with playing since... I'm gonna take it back to the shop again - they said they'd replace the string, but they're convinced it's something to do with the bass itself. The last E string didn't do anything like this (it was just dull as I'd been playing with it for about 6 months). It's worth emphasising that this is the basses first string change since I bought it, it's a Fender Jazz Actve Deluxe 4 string and the strings I've put on it are the heaviest guage available (apparently). They're nickel roundwounds.