Rewired Strat: Now Tone at 100% Kills Volume

Discussion in 'Luthier's Guitar & Bass Technical Discussion' started by nola geoff, Jul 13, 2008.

  1. nola geoff

    nola geoff Member

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    I just wired a set of Lindy Fralin pickups into my strat (replacing lace sensors).

    Everything worked fine the first time -- except I was getting some hum from the dimmers in my house. I decided to pull it back apart and shield the cavity (using the technique outlined at guitarnutz.com http://www.guitarnuts.com/wiring/shielding/shield3.php

    Now it sounds great . . . with one problem. When the middle tone knob is at 100% open, it kills the volume. Nadda. Dead silence. If I back off the tone knob just a bit, then the guitar kicks in at full volume.

    I suspect that this could have something to do with the tone knobs essentially acting as a bypass at 100% and perhaps that is creating some kind of short. But my knowledge of this stuff is VERY limited so I could be way off base.

    The only place I deviated from the guitarnutz procedure is that I could not find a .33uF 600 volt cap and so I used a 1uF 250 volt. I don't think that is the problem but I could be wrong.

    Any help will be greatly appreciated.
     
  2. AndrewSimon

    AndrewSimon Member

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    You have a short on the tone control.
    The leg that goes to the cap is shorted to the ground....
    or the cap itself is shorted (very unlikely)
    Most likely there is a ground wire touching the pot leg.
    Did you try to troubleshooting with the pickguard off?

    If you need further help please provide pictures.
    :cool:
     
  3. Rosewood

    Rosewood Member

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    The pot may also be touching the shielding.
     
  4. RussB

    RussB low rent hobbyist Silver Supporting Member

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    A 1uf cap is a big cap! so is a .33uf. Are you getting the decimals correct?
     
  5. walterw

    walterw Gold Supporting Member

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    yeah, you want more like a .033 cap, and the voltage rating doesn't matter. make sure the tabs on the tone pot aren't touching that shielding foil, or anything else.
     
  6. nola geoff

    nola geoff Member

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    Hi Everyone,

    Thanks for the assistance. I had a gig yesterday and am playing tonight as well so it may be a few days before I can try and track this thing down.

    In the meantime, one of the challenges I have is that since this is a strat with the strings-through-the-bridge set up, each time I work on it I have to take it completely apart and then put it all back together.

    Once I take it apart again, I would like to confirm that I have solved the short before I put it all back together. I assume there is a way I can track down this short with a volt / ohm meter but I haven't used one in 15 years or more. If it is possible to use this as a tool to track down the short, can anyone offer assistance in how I would do this. Also, will a $20 meter work or do I really need a nicer one?

    RE: the large cap:

    This isn't a cap that is being used on the tone control (I am using a .022 for that). This is part of a mod that is designed to soften the blow from a rare but potentially fatal shock hazard should you end up between a club's bad wiring and ground. If you follow the link in my original post there is some detailed info but my understanding is that the large cap takes most of the hit so that you receive a nasty bite but there won't be enough punch to stop your heart.

    Best,
    Geoff
     
  7. walterw

    walterw Gold Supporting Member

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    oh, my bad for not RTFM, er, link. i've done pretty much the same set up to my tele (all metal parts lifted off of ground via a big cap, all grounds to one point.) i had to bump up to a 2uF cap, as anything smaller left noise that wouldn't go away upon touching metal.
     

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