I recently had the privelige of playing a blues gig using a friends '65 Jazz Bass equiped with Barts (don't know which model) the rest of the electronics were stock AFAIK. This thing was nothing short of AMAZING. Played with a light touch the sound was big and round, dig in and the growl & sizzle would just leap right out, slap and pop sounded great too, and of course backing off the neck pickup got that tight Jaco sound.
I know I wont nail the tone of the '65 Jazz spot on, but I'd like to get somwhere in the ballpark. The use of words like growl and sizzle fall short to describe what I'm after, so I edited a fairly short MP3 clip from said gig. I've tried to post it but for some reason it won't upload.