PJ volume issue

Discussion in 'Pickups & Electronics [BG]' started by mfowlkes, Dec 5, 2013.


  1. mfowlkes

    mfowlkes Supporting Member

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    I just purchased a Road Worn p bass body with a 60's position jazz route. I bought a set of Aguilar PJ pickups with j hum canceling split coil. Without too much modification, I used a stacked pot for V/V, tone, input on the pickgaurd. The sound is awesome when either pup is solo'd and no hum. But with both pups volume on full, the overall volume drops 50% and sounds like a dying goat. There is really no blend when adjusting the volumes.

    I've wired over 20 p basses but this one being my first PJ. Any tips to what maybe causing this? I can provide a wiring photo later.

    Help!
     
  2. nervous

    nervous Supporting Member

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    Possible phase issue between the pickups? I just had a similar issue but was using an active pre. Might be an easy thing to rule out by simply swapping the wiring polarity on one of those where they attach to the pot.
     
  3. line6man

    line6man

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    Yeah, sounds like the pickups are out of phase.
     
  4. mfowlkes

    mfowlkes Supporting Member

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    Sorry for the bad diagram. Made a quick sketch using the iPhone of the current wiring setup I have.

    ImageUploadedByTalkBass1386538268.486670.jpg
     
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  6. Arvin

    Arvin Underwound Supporting Member

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    Choose one of the pickups to work with; I'd recommend choosing whichever one it's easier to get to the leads (looks like maybe the P?).

    Desolder the leads and reverse them -- put the black lead where the white one was, and vice-versa -- and resolder them.

    That should fix your problem.
     
  7. line6man

    line6man

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    Your tone pot is wired backwards. Though that is something unrelated to the issue you described.
     
  8. jcanderson

    jcanderson

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    Are the right-hand terminals of both V pots tied to your common ground? They should be. Can't tell from the drawing.

    Also, no ground shown between tone pot and V pots. Metal control plate, or plastic?
     
  9. line6man

    line6man

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    There is a connection between those pots, otherwise there would be no output. So that doesn't matter.
     
  10. mfowlkes

    mfowlkes Supporting Member

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    Yes, the pots all have a common ground that leads to the bridge. Copper shielding on cavity and plastic pickguard. Also the right terminals of the stacked pot are grounded.
     
  11. jcanderson

    jcanderson

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    It was clear that the jack had to be connected to pickup gnd. But apart from that, you could have missing gnds (as drawn) and still have an output.

    For example, there is still a complete circuit even if the volume pots are NOT connected to ground. The pots would now be in series with the pickups, rather than shunting them.
     
  12. mfowlkes

    mfowlkes Supporting Member

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    Thanks for all your responses! I hope to resolder this afternoon.
     

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