2-humbucker, coil-tap, wiring question!

Discussion in 'Luthier's Guitar & Bass Technical Discussion' started by Heady Jam Fan, May 16, 2016.

  1. Heady Jam Fan

    Heady Jam Fan Member

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    I'm hoping someone can help me with a wiring diagram for a 2-humbucker guitar. The specs include:
    - 2 4-conductor SD 59 Humbuckers
    - 1 Volume
    - 1 Tone
    - 1 3-way Pickup Selector Toggle
    - 1 Master Coil-Tap
    - Bridge Pickup Wired for a RWRP thing (the slug coil is active in coil-tap mode on the bridge pickup, while the neck pickup's screw coil is active in coil-tap).

    I have a guitar that is supposed to be wired this way, but I think the tech might have messed something up:
    - I think he switched which coil is active in coil-tap mode (I think he has the neck's slug and the bridge's screw coil).
    - In the in between setting on the pickup selector, I don't hear any difference between coil-tap and humbucker mode. I think something is happening where the coils are tapped in the in-between setting regardless of the coil-tap switch.

    The closest diagram I could find is this:
    [​IMG]
    I don't know if it matters, but it looks like this diagram is depicting a push-pull tone knob rather than a mini-switch for coil-tapping. This also doesn't have the reversed bridge pickup.

    Here is another, but I don't need the master-series switch:
    [​IMG]

    Thank you in advance!
     
    Last edited: May 16, 2016
  2. Heady Jam Fan

    Heady Jam Fan Member

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    Below is a pic of the "on-on" mini toggle in my guitar.
    - Are these wires soldered to the correct lugs on the switch?
    - Are the red & white wires switched from the bridge pickup?
    [​IMG]

    On the switch, the lower/left lugs are connected to ground and the middle lugs are soldered together. The top/right lugs are connected to the pickups: further/leftish one is connected to the red & white conductors from the neck pickup, and the closer/rightish is connected to black & green from the bridge humbucker.

    From the neck pickup, the black conductor is going to the pickup selector, and the green & shield are going to ground (back of volume pot).

    From the bridge pickup, white is going to the pickup selector, red & shield are going to ground.
     
  3. walterw

    walterw Gold Supporting Member

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    you can confirm by setting your amp clean, then tapping on each coil with a little wrench or screwdriver to see which ones are active. the "off" coils will still make sound, just quieter than the "on" coils.

    the trick with reversing the wire colors around is legit, it lets you use ground to switch both pickups to single coil while leaving the opposite coils on for hum-canceling.
     
  4. Heady Jam Fan

    Heady Jam Fan Member

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    Thank you! I really appreciate the help.

    I couldn't tell using the tapping with a wrench trick (I used a small metal wire that I plucked, maybe I'll try with the wrench).

    I did some more exploring and found this:

     
  5. walterw

    walterw Gold Supporting Member

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    a wire might be copper, which won't tell you anything (being non-magnetic).

    any ol' piece of non-stainless tool steel, like an allen wrench, screwdriver, scissors, bottle opener from the kitchen, whatever.

    hold it so that it's only over one coil at a time and tap on the coil. (again, set the amp totally clean.)
     
  6. Heady Jam Fan

    Heady Jam Fan Member

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    Will do! I'm probably bringing the guitar with me to work so I can swing by the tech on my way home. I'd like to fix it myself, but I'm ridiculously busy (so I'd rather spend my time playing) and I don't have great solder gear around right now. I want to make sure I figure out the wiring before I go see the tech tomorrow.
     
  7. Heady Jam Fan

    Heady Jam Fan Member

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    Interestingly, according to Seymour Duncan, their standard coil-tap sends the screw coil to ground and keeps the slug active. I would have thought it would be opposite.

    [​IMG][​IMG]
     
    Last edited: May 17, 2016
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  8. Heady Jam Fan

    Heady Jam Fan Member

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    And here is their mini-toggle, master coil-tap wiring diagram (finally found it)
    [​IMG]
     

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