Epiphone Jack Cassidy wiring

Discussion in 'Pickups & Electronics [BG]' started by Waxwing, Nov 21, 2012.


  1. Waxwing

    Waxwing

    Joined:
    Jun 21, 2012
    I have the JC bass that has a couple of issues. 1 - output seems low, 2 - no perceivable change when switching the varitone. I have a schematic but this bass is not wired at all like the schematic. According to other threads, it's not uncommon for this bass wiring and the schematic to be quite different.

    My electronics troubleshooting skills are not the best so I'm hoping someone out there knows something about the wiring. If I posted a photo of my wiring, can someone check it over and see if there is any reason for the above two problems?

    I would really appreciate any assistance!

    Attached Files:

  2. SGD Lutherie

    SGD Lutherie Supporting Member

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    It should look like this:

    Attached Files:

  3. Waxwing

    Waxwing

    Joined:
    Jun 21, 2012
    Thanks! Your wiring diagram looks a lot like the schematic but I'm no expert. At least the pot wiring looks the same, but I get lost at the switch and transformer. My bass does not have any caps or resistors wired to the pots and my pots are 25k, not 2.5k as indicated on the schematic. Have you actually wired up a bass following this wiring diagram and it worked? Should I stick with my 25k pots or try to find 2.5k pots? Thanks, really appreciate your help. I'd be lost without it!
  4. SGD Lutherie

    SGD Lutherie Supporting Member

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    Did someone rewire that bass?
  5. Waxwing

    Waxwing

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    Jun 21, 2012
    Yes, I think someone has done some work on it before I got it.
  6. SGD Lutherie

    SGD Lutherie Supporting Member

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    OK, I'm suspecting that the pickup are not going to the transformer, and that's why the output is low, and the impedance selector switch (varitone) doesn't work. They are low impedance pickups, so you either need the transformer or a preamp to get the levels up.

    Is the transformer still in the bass? You need to get it wired up like the schematic.
  7. Waxwing

    Waxwing

    Joined:
    Jun 21, 2012
    Yes, the transformer is there, just not wired like the schematic. It's totally different. What do you think about the pots? Should I use the 25k or try to find 2.5k? Lowering the resistance value of the pots will make the tone a bit more warmer ... is that right?
  8. Waxwing

    Waxwing

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    Jun 21, 2012
    Talked to Gibson tech support. Here's the schematic they sent to me.

    Attached Files:

  9. Stealth

    Stealth Supporting Member

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    Feb 5, 2008
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    Zagreb, Croatia
    I'd say Gibson messed up the values - those should definitely be 25Ks, not 2.5Ks.

    David, is that from the big bad book of wiring by Cadfael? Amazing PDF, that. :D
  10. SGD Lutherie

    SGD Lutherie Supporting Member

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    Owner, SGD Music Products
    No, it's 2.5k. The pickup only reads 23.3 ohms!


    Yes it is. :) Now I have to learn German ... (You would think I would know some with my last name!)

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