Solutions for vibrating/microphonic pickup mounting screws?

Discussion in 'Luthier's Guitar & Bass Technical Discussion' started by johnny q, Feb 15, 2009.


  1. johnny q

    johnny q Member

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    The condition: A loud "whooooooo" sound when playing at high volumes. The solution: Placing your fingers on top of both pickup mounting screws = dead silent, no microphonics.

    I have heard everything from bending the screws, replacing the screws, placing foam under the pickup - what has worked for you guys?

    JQ
     
  2. Hargrett

    Hargrett Member

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    Sounds like a microphonic pickup to me. If you can speak into the pickup and hear your voice through the amp, it's microphonic. I guess any of the things you mentioned might dampen or torque the pickup enough to help for a while, but if it's microphonic the best bet is probably to re-pot or replace the pickup.
     
  3. johnny q

    johnny q Member

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    I have had microphonic pickups before, and placing your fingers on the mounting screws certainly did not stop the feedback - I dont think potting is the culprit, I suspect loose screws.

    I could swear someone told me that bending the screws in the middle a few degrees fixes the problem, but I was hoping to hear that from someone that knows more than I do about this stuff.

    JQ
     
  4. Hargrett

    Hargrett Member

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    I thought that maybe by touching the mounting screws you were dampening the pickup enough to stop the problem. Some teflon tape (plumber's tape) on the mounting screws will tighten the fit. Bending them will probably torque the pickup a little... might work. While you have the screws out, plug it in, turn it up, and see if it howls without the screws. I've never heard of a microphonic problem actually being caused by the mounting screws, but I'm here to learn! By the way, what kind of guitar is it?
     
  5. johnny q

    johnny q Member

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    Its in a PRS Custom 22. Its an uncovered Suhr Aldrich model. Great pickup btw!!! I have some plumbers tape, I will give that a try.
     
  6. Hargrett

    Hargrett Member

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    Hope the tape works! The most surprising microphonic problem/fix I've run across lately was a squeal coming from my satin nickel-covered Duncan JB bridge pickup at high volumes, whch went away when I changed my volume pot from a 500K to a 300K. You never know!
     
  7. Husky

    Husky Gold Supporting Member

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    A microphonic pickup squeals (high pitch), howling (low pitch) is different and has to do with gain, loudness and acoustic properties of the pickup interacting with the speakers.

    Foam under the pickup, make sure the pickup is not touching the body not locked down (floating) and a Neoprene O ring under the head of the screw so the screw doesn't touch the pickup.
    This last tip comes from Tom Anderson, I haven't tried it but he says it works.:dude
     
    Last edited: Feb 17, 2009
  8. johnny q

    johnny q Member

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    A neoprene O Ring.....now THAT sounds like something to try!:dude
     

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