I installed it in my Fender Highway-1 Jazz Bass, in place of the regular tone potentiometer, and wired the switch part of it to change between two different wiring modes for the pickups:

• Parallel – Which is the default on the Jazz Bass. In this mode each pickup gets a volume knob.
• Series -Connecting the pickups in series, so that they act as one. This delivers higher gain out of the pickups, and a punchier tone. When in series mode, you only get one volume knob that controls both pickups.

I used the following diagram that I had found online:

It took me about 45 minutes to assemble, because soldering was a bit tricky, and I forgot one connection after fastening all the screws back.

I have no proper way to record my bass on the computer, so no sound samples for now. All I can say is that I’m very pleased with this new sound of my bass.  I still have to try it on a serious amp to get a better idea of the new tone.

If you own a Jazz Bass, not afraid to void your warranty, and can solder (or get someone to solder it for you), I’d suggest you to try this mod.