Wiring question/help please

[skydog]

I’ve wired up 2 P90’s with 2 V pots only. They both work fine independently, but when both pups are selected, both V pots have to be turned up equally. Each acts as a MV otherwise. I’d like to be able to adjust them independently. It is wired as below:

 

[beaubrummels]

That diagram should work. Must be something specific to the wiring you did. That diagram is for 4-conductor humbuckers. How did you wire the P-90s, exactly?

 

[skydog]

They are only 2 wire, so black to ground.

 

[Artie]

You need to reverse the input and output of the volume pots to get quasi-independent vol controls. It's not perfect, because as you lower the pot, you increase the "load" on the pup, thus altering it's character. But there's no good way to implement a passive mixer.

Actually, there is, but it requires two dual-gang 1-meg pots, which aren't easy to find. Not concentric, but ganged. One shaft, one knob, per pot. I'll try to find the diagram if you want to attempt it. The actual wiring is dirt simple.

 

[Artie]

Wire it like this. Assume the shield to be the black wire, and the center conductor to be the white wire. Omit the tone control.

https://www.seymourduncan.com/images/wiring-diagrams/JazzBass_Standard.jpg

 

[skydog]

Wire it like this. Assume the shield to be the black wire, and the center conductor to be the white wire. Omit the tone control.

https://www.seymourduncan.com/images/wiring-diagrams/JazzBass_Standard.jpg

That doesn’t include the toggle, but I think it’s what I have other than that.

 

[Artie]

The important thing is to reverse the wires at the red and green arrows. (On both pots.) Ignore the red/white, since you don't have them.

 

[skydog]

The important thing is to reverse the wires at the red and green arrows. (On both pots.) Ignore the red/white, since you don't have them.

Thank you! That made all the difference!

 

[Artie]

Glad I could help.

 

[zionstrat]

Glad I could help.

Arty, I'm pretty sure you've tried to explain this before, but could you help me understand why reversing the wires makes this work better?

 

[Artie]

Because , if you ground one pup, you ground both. You have to isolate one from the other. Let me find my pic.

 

[Artie]

Like this:

 

[Artie]

The first diagram doesn't show the caps. You want to do the caps.

 

[Mincer]

I know it is impossible to create and archive every diagram possible, but man, I wish a project like that was started 20 years ago. And the most important thing...correct diagrams.

And while I love the SD wiring course, it would be great to have some sort of wiring theory course that would allow people to easily modify diagrams because they would understand how it all works.

 

[Phantasmagoria]

Sweet! Now that's theory I can use :bigthumb: