PJ bass wiring problem

[David Schwab]

use a 6 string pickup with a dummy magnet?

That would work. However, you can't fit two equal size coils into a Jazz bass pickup cover.

[TJBass64]

Welcome TJB!
When you got the phase straightened out was there still some hum with the VVs all the way up?

Glad you asked....I had just re-wired the bass last night and only checked the sound through my pc.
I just checked the bass, first with only the amp on ( markbass f500 connected to a 15" jbl in a kroth cab) and there was a slight hum with the grd lift on. tolerable. then plugged the bass in with vv's all up,not touching the strings or any other ground to the bass.
results.... slight buzz only on the p with the t nob up... which dissappears when then string are touched. no noise on the j at all at full tone . buzz dissappears completely with all combos of v's with the tone full down. I am pretty impressed with the results being that the bass is passive. I'll work on getting some pics to post ....

[David King]

Interesting results, I gather that the J pickup is some sort of humbucker.

[TJBass64]

as I said earlier.... the wires from the pu are shielded . a white, a red and the bare shield around both . they are attached to some sort of plate that shields the pu. wish I could i d the pu .... older model... maybe a fender noiseless ???
Got it for 35 bucks about 20yrs back from a local guy that worked at a music store. It's all about the tone and I'm quite happy now that the "cut out" issue is gone.

[verhoevenc]

I’m dealing with this right now with a build and it’s driving me crazy! With the P and J both at max in a VVT setup you get a dull, volume cut, sound. Moving back either volume even a tiny bit makes all the difference. Someone told me to swap the J’s leads to fix polarity, this made things worse if anything so I put them back to normal. Now someone is saying flip the magnet polarity on the J which I’m skeptical of since the lead swap didn’t help. Reading the above (provided I understood it correctly) matched my initial thoughts that a humbucking P and an SC J can never work perfectly with both maxed. Let me know if this sounds right to you? It seems logical since the two P coils are always going to be RWRP to each other... and adding ANY single oil to that mix is going to lead to at least half the strings being OOP... right?
Chris

[copperheadroads]

I've had to deal with this a few months ago , I think a switch to switch between the pickups would correct the problem with the canceling when both volumes are on full.

[verhoevenc]

Actually, I just drew it all out and it appears you can get all strings INPHASE with both on. Example, my J is south-up. The P is south-up on the low strings and north-up in the high strings. Therefore, if the J is CW, the high string P is CCW, and the low string P is CW then you should get RWRP high strings and in-phase, but not humcancelling, low strings. This is what I believe I have as I mentioned earlier a wire-swap of the J made things worse... especially the high strings... aka: OOP. This still doesn’t address why there’s a dull drop with both maxed though... sigh.
Copperheadroads, why do you believe a switch would work better than 2 volumes? I don’t follow?

[verhoevenc]

OMG!!! I wish I had just done this exercise earlier!!! I went and actually investigated better... here’s whats going on:
J: south CCW
P low: south CW
P high: north CW
WHOEVER WOUND THIS PICKUP SCREWED UP THE WIND DIRECTION OF THE P LOW!!! So much time wasted... :|
Chris

[StarryNight]

WHOEVER WOUND THIS PICKUP SCREWED UP THE WIND DIRECTION OF THE P LOW!!! So much time wasted... :|
Chris

the wind direction of both coils can be the same if the start of one coil is connected to the start of the other (or end of one connected to the end of the other). It will be humbucking.

[verhoevenc]

Sorry, I should have been clearer. Yes, both winds can be same direction and still work as long as the leads are hooked up right. These leads were not hooked up right hahahah. At least it’s a fairly simple fix.
Chris

[copperheadroads]

Actually, I just drew it all out and it appears you can get all strings INPHASE with both on. Example, my J is south-up. The P is south-up on the low strings and north-up in the high strings. Therefore, if the J is CW, the high string P is CCW, and the low string P is CW then you should get RWRP high strings and in-phase, but not humcancelling, low strings. This is what I believe I have as I mentioned earlier a wire-swap of the J made things worse... especially the high strings... aka: OOP. This still doesn’t address why there’s a dull drop with both maxed though... sigh.
Copperheadroads, why do you believe a switch would work better than 2 volumes? I don’t follow?

Look up something called "insertion loss"
.

[David Schwab]

Sorry, I should have been clearer. Yes, both winds can be same direction and still work as long as the leads are hooked up right. These leads were not hooked up right hahahah. At least it’s a fairly simple fix.
Chris

I've seen P pickups done both ways. P basses only have one pickup, so the two halves don't have to be in phase with a second pickup.

But the other issue with a P/J setup is they just don't match very well. The P overpowers the J.

[verhoevenc]

Sure, but this was given to me as a PJ set so I would have thought that that would be taken into account.
As for the "overpowering" comment, I sort of agree. It was a fun little project but in the future I probably won't do any more PJs unless asked to.
Chris