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Jazz Bass pickup wiring question

Discussion in 'Luthier's Corner' started by Philthy, Jun 13, 2002.


  1. Philthy

    Philthy Supporting Member

    Jun 12, 2001
    Wallington, NJ
    I recently modified my jazz bass by replacing the bridge pickup with a Bartolini musicman style Humbucker (wired in Parallel). Each pickup has it's own independent volume pot as Jazz basses do. When I turn up each pickup volume individually (keeping the other turned off), I get a nice loud, bright sound; as I should. Then when I turn both pickup volumes all the way up, I get a significant volume drop. Why is this? Then if I turn one of the volume pots back a hair, the volume increases again.

    Any idea why this is happening and what can I do to fix this?
     
  2. thrash_jazz

    thrash_jazz

    Jan 11, 2002
    Ottawa, Ontario, Canada
    Artist: JAF Basses, Circle K Strings
    Off the top of my head, I can think of one thing (which may be way off): The pickups may somehow be interfering with each other. If you combine an MM with a J pickup, could they be out of phase somehow? I don't think they were designed to work with one another. If that IS the problem, I don't see what can be done, short of changing one or both of the pickups again.
     
  3. pilotjones

    pilotjones Supporting Member

    Nov 8, 2001
    US-NY-NYC
    As you combine the pickups, does it start sounding thin and trebly or "hollow" as well as lower in volume? If so, the pickups are ot of phase with each other. To remedy this, reverse the connections of the two output wires of one of the two pickups.
     
  4. Philthy

    Philthy Supporting Member

    Jun 12, 2001
    Wallington, NJ
    Yes. When I combine them and both volumes are up, they drop significantly in volume and it sounds hollow and trebley. That's exactly what happens. So, I should reverse the wires of one of the pickups? I assume you mean reverse the hot and ground and switch their places that they are soldered to the volume pot, right?

    Thanks for your help.
     
  5. pilotjones

    pilotjones Supporting Member

    Nov 8, 2001
    US-NY-NYC
    Exactly. Do it with the output of one of the PUs, but leave the other one alone. Let us know how it comes out!
     
  6. Philthy

    Philthy Supporting Member

    Jun 12, 2001
    Wallington, NJ
    Awesome!!!! I tried it out this weekend and it worked. The bass sounds great. Thanks for your help!!!
     
  7. pilotjones

    pilotjones Supporting Member

    Nov 8, 2001
    US-NY-NYC
    Glad to be of service.