I'm getting a Fender mim standard jazz within the next few weeks and I've een hearing alot about this mod. I've got a bit of an idea what it does but can someone explain to me. What exactly it is. What it does. Is it worth it? How much should I have to pay. Overall advantages. Sound properties.
I think I am right in saying that the switch you refer to is the one which is currently fitted as standard to the American Series Jazz Bass. It is referred to as the S-1 switch. It is operated by depressing the volume knob of the neck pickup. The bridge pickup is in then cancelled out and the pickups are switched between series and parallel. It gives a sound similar to a Precision bass. By depressing the knob again releases the switch back to normal Jazz operation. I hope this helps.
I played with an S1 switch equipped USA Jazz the other day at Guitar Center. In the series mode (switch depressed) the lows were fatter and it was slightly louder. It was a subtle difference... IMO suitable for bedroom tone only, as I know that I'd never hear the difference on the bandstand. Maybe others could, but I'd be surprised...unless it was a quiet bass solo or something. You could probably get a schematic at www.fender.com Basically, you'd need a DPDT (double pole, double throw switch) that could either be a push on/push off (like the S1) a pull on/push off pot or a dedicated toggle switch. One section of the switch would connect the hot lead of the bridge pickup to either its volume control (parallel mode) or the negative of the neck pickup (series mode) and the other section would either connect the neck pickup's negative lead to ground (parallel mode) or the hot of the bridge pickup (series mode). Pretty simple stuff (although it might not read that way).
I had bookmarked the following post for the same interest. Check this in addition to the stickys in the Pickups forum. http://www.talkbass.com/forum/showpost.php?p=2430865&postcount=12