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Homemade preamp issue - won't turn off all the way

Discussion in 'Pickups & Electronics [BG]' started by Cougmeister, Feb 18, 2013.


  1. Cougmeister

    Cougmeister

    Joined:
    Oct 1, 2012
    recently I converted my MIM Fender Deluxe Jazz V to passive with a VVT control with a push/pull series/parallel switch in the neck pickup volume pot. Everything seems to be working correctly, other than the fact that i still get sound out of it even with all of the knobs turned off. What could the issue be?

    Both of the volume pots are 500K and the tone is a 250K

    Here's the diagram I followed. Ill put up a picture of the actual wiring shortly.
     

    Attached Files:

  2. line6man

    line6man

    Joined:
    Jun 20, 2008
    Location:
    Close to Los Angeles, CA
    Your pots are not grounded properly.
     
  3. Cougmeister

    Cougmeister

    Joined:
    Oct 1, 2012
    How do I properly ground them? They are all grounded to the bottom of the pot as pictured.
     
  4. seanm

    seanm I'd kill for a Nobel Peace Prize!

    Joined:
    Feb 19, 2004
    Location:
    Ottawa, Canada
    Did you bend up the one leg of the volume pots and solder them as shown?
     
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  6. SGD Lutherie

    SGD Lutherie Banned

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    Aug 21, 2008
    Location:
    Bloomfield, NJ
    Disclosures:
    Owner, SGD Music Products
    Where is the homemade preamp? It's a passive bass. There is no preamp.

    But as the others have said, your volume pots are not grounded.
     
  7. Cougmeister

    Cougmeister

    Joined:
    Oct 1, 2012
    I did as best as I could. The solder wasn't wanting to bond with the bottom of the pots. It was kind of a botch job, so I'm thinking about rewiring it to make sure I have solid connections.
     
  8. SGD Lutherie

    SGD Lutherie Banned

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    Aug 21, 2008
    Location:
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    Disclosures:
    Owner, SGD Music Products
    Some pots are plated, so you have to scratch the metal up a bit.

    If you can't get the solder to stick, just run a wire from the tab that's supposed to go to ground, and ground it to the output jack along with the other grounds. Then solder your pickup grounds to that tab on the pot.
     
  9. Cougmeister

    Cougmeister

    Joined:
    Oct 1, 2012
    Ok, got it fixed, but I still have some hum going on, but it quits when I touch anything metal on the bass. Could this be a poor bridge ground connection?
    It's all unsheilded by the way.
     
  10. SGD Lutherie

    SGD Lutherie Banned

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    Aug 21, 2008
    Location:
    Bloomfield, NJ
    Disclosures:
    Owner, SGD Music Products
    If it stops when you touch the strings, then the string ground at the bridge is fine.

    It could be the lack of shielding, and/or a bad ground connection where the amp is plugged into the wall.
     
  11. Cougmeister

    Cougmeister

    Joined:
    Oct 1, 2012
    Ok. The power strip I'm plugged into says that the wall plug isn't grounded.
     
  12. SGD Lutherie

    SGD Lutherie Banned

    Joined:
    Aug 21, 2008
    Location:
    Bloomfield, NJ
    Disclosures:
    Owner, SGD Music Products
    That's probably it.
     
  13. Cougmeister

    Cougmeister

    Joined:
    Oct 1, 2012
    Good. Thanks for the help!
     

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