P/J setup Buzzing?

[M.R. Ogle]

I had a friend who liked the setup of the controls of my Jazz bass (one vol, series/parallel switch, one tone) and so we wired his P/J pickups the same way.
It DOES work the same way, but it also seems excessively noisy, picking up buzzing pretty much all the time. Touching the strings/bridge reduces the buzz, but it still is there.

Is this because the P part of the equation has a naturally humbucking, one coil reversed config and it's not playing nice with the J pickup? Or could there be something else going on?

I can't really figure this one out. My Jazz does not do this at all, and the wiring is identical. Electronics gurus, I'm open to suggestions, THANKS!

 

[khutch]

The P pickup is hum canceling, the J pickup is, I presume, a single coil and this setup will be just as susceptible to hum pickup as a single coil would be. Your two J pickups will hum cancel whether you put them in parallel or series so the Jazz bass arrangement is going to be quieter. Part of the difference between the two basses could also be grounding or shielding differences but the P/J is always going to be more susceptible to hum pickup. If you are going to wire a P/J this way then you want a hum canceling J pickup of some kind and if your friend likes single coil J pickups then a split coil J will get him a similar sound. On a VVT or BVT P/J you have the option of turning down the J pickup if it picks up hum, with no volume or blend control to kill the J pickup you really want to use a split coil, stacked coil, or some other kind of hum canceling pickup for the J. Or you could route it out for a MM humbucker!

 

[M.R. Ogle]

That was our initial thought, get a noiseless J pickup for the setup.

 

[LoveThatBass]

That was our initial thought, get a noiseless J pickup for the setup.

I tried putting a P and J in series with the same results. Just doesn't work well

 

[M.R. Ogle]

I liked the sound, but was quite surprised by how noisy the circuit was. A little hum, I can put up with that, I have a SCPB. But this was an all-the -time annoyance. No way you'd ever be able to use that in a recording session.

 

[DiabolusInMusic]

The fact the hum goes away when you touch metal indicates RF noise. I would give the bass a proper shielding job to reduce the noise considerably. It will still get 60hz hum since the jazz p/u is a single coil.