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Wiring Issue With Dimarzio ultra jazz

Discussion in 'Luthier's Corner' started by Skorzen, Oct 27, 2004.


  1. Skorzen

    Skorzen

    Mar 15, 2002
    Springfield MA
    Ok if the mods feel like this should be in the pickups forum feel free to move it, I felt it would get more attention here.

    Here is the deal, I just finished the bass I have been working on that I put Dimarzio Ultra jazz 5s in. It also has a two band bartolini pre in it(ntbt?) The issue is that the bridge pickup buzzes ridicously. The neck pickup is fine. I went back and shielded both pickup cavities, and that made no difference. Something else I noticed is that when the two pickups are panned to the middle the D and G strings(second coil of the pickup) sound weak(ie out of phase) the other three strings sound fine.

    Noe this is my theory at this point is that the the internal wiring on the bridge pickup was wired in parallel at the factory rather than series as it was supposed to be. I did try reversing the phase on the bridge pickup and had a similar effect on the B E and A strings. So by being wirired incorectly they are not canceling hum as well as being out of phase on one coil with the neck pickup.

    Does this make sense or am I completely off my rocker? any ideas?
     
  2. pilotjones

    pilotjones Supporting Member

    Nov 8, 2001
    US-NY-NYC
    It's not a series/parallel issue, as both can be done humbucking. What you have is that one of the two coils in the bridge pup is reversed, so two things happen - it is no longer humbucking, and depending on the overall wiring, either one coil or the other is out of phase with the neck.

    Reverse one of the coils to get it back into humbucking with itself, and then put the entire pickup in proper polarity to work with the neck pup.
     
  3. Skorzen

    Skorzen

    Mar 15, 2002
    Springfield MA
    thats, kinda what I was saying, but I guess I used some of the wrong terms. The coils and everything are all glued into the cover with wax. I just wanted to make sure that there wasent some easy way to go about fixing this without modifying the pup itself. I talked to Dimarzio, and they said to send it back. I just wanted to make sure I wasent overlooking something.
     
  4. pilotjones

    pilotjones Supporting Member

    Nov 8, 2001
    US-NY-NYC
    The DM UJs only have two wires for output?
     
  5. Skorzen

    Skorzen

    Mar 15, 2002
    Springfield MA
    the 5 string ultra jazz has three wires a red a gray and a green. the red is hot the green geen and gray are soldered to ground.
     
  6. pilotjones

    pilotjones Supporting Member

    Nov 8, 2001
    US-NY-NYC
    Yes, sounds like two wires plus ground, meaning it's wired wrong internally. You don't have access to the internal four wires plus ground to fix it yourself.