SPB3 Wiring Diagram Has an Error. Here is the fix:

[NCD]

I hope that this can save many of you who are installing your own SPB3's a lot of headaches.

Short, short version:

This is the standard diagram, straight from SD:

[Invalid or Expired Link Removed]

Look carefully. If you know electronics, trace the ground from the jack shield to the tone pot body... and then what happens? *Poof*

The bridge ground wire goes to the volume pot body, but there is nothing grounding the volume pot body in that diagram... there is supposed to be a wire between the pot bodies OR you can run a second one straight from the jack shield to the volume pot body.

When I wired exactly per the diagram, my pots were horrid, scratchy and had tons of popping static. I also got zapped on the volume pot nut when plugged into an amp... but there is nothing wrong with the amp, it was due to the pot not being grounded.

Adding a ground wire to the volume pot fixed every problem I had.

This is the thread I started while figuring out the issue:

http://www.talkbass.com/forum/f38/s...now-scratchy-dirty-grounding-question-856622/

 

[line6man]

That's not an error. Usually the ground connection is made through the shielding. Some prefer to also solder a wire between the pots, to make a solid, non-mechanical connection.