PJ - Series/Parallel wiring

[Serginhobass]

Hey everyone! 

 

I’m planning to rewire my Yamaha BBP35 (PJ configuration) and would love to get some feedback from those more experienced with bass wiring.

 

Here’s what I’m aiming for:

Volume: 250K push-pull pot (for series/parallel switching between P and J pickups)

Blend: CTS EP-6386-000 500K MN taper pot

Tone: ToneStyler Bass 10

 

My goal is to have:

• Push in → pickups in parallel (standard PJ setup)

• Pull up → pickups in series (fatter, more powerful tone)

 

I’ve drawn up a wiring diagram showing how I think everything should connect, and I’ll include some photos of the pots I’m using.

 

Before I start soldering, I’d really appreciate any feedback or corrections, especially around:

• Whether my series/parallel switch wiring looks correct given both pickups only have two wires

• How best to ground the blend pot and push-pull pot to avoid hum

• Any other improvements or common pitfalls I should watch out for

 

Thanks in advance for taking the time to look! I know a few of you have done similar PJ rewires, and I’d love to learn from your experience. 🙏

[itu]

Solder ground to output. Don't rely on the screw contact on a metal plate. Pot cases should be soldered, too. Use a file to scratch the surface for easier soldering. 

 

When assembling the harness to the bass, check that none of the wires or parts touch the body. You should paint (conductive) or use copper tape to shield the cavities and ground them to the harness. 

[Serginhobass]

Thank you for the advice @itu 🙏  

[Serginhobass]

Quick update on this post. Please DO NOT follow the diagram I shared above, it is wrong! 
 

After many emails exchanges with Don from StellarTone he was super kind to helped me fix this diagram. I’ll attach a picture of how it should be, below.
 

I also decided to change the volume pot for a CTS 250k push pull pot. 
 

In the end I paid someone to do these changes as I could not trust my soldering skills. If you are good with soldering that’s a no brainer mod. I think it’s totally worth the investment. 
 

Please see the links for all the components used:

Volume push pull pot

https://ebay.us/m/eK4hvR
 

CTS blend pot

https://ebay.us/m/OQenuP

 

ToneStyler Bass 10

https://www.bassdirect.co.uk/product/stellartone-tonestyler-bass-ten/

 

Note: The series mode only works as both pickups on, and if you have the bridge pickup soloed it will mute the bass. So for Series sound you have to have the blend at center or at neck pickup. 
 

Correct wiring diagram:

 

 

Edited 18 hours ago by Serginhobass

[Serginhobass]

Here is a video I recorded to give you an idea of the amount of tonal possibilities with this mod. 

For me it is the best mod for a PJ, particularly for the BBP bass as I always found it lacked a distinct tone range. 
 

The best thing is, it’s all passive!
The sound in this video is straight from the bass to the recorder. 

 

 

Edited 18 hours ago by Serginhobass