TrebleTone Loss on Volume Knob(PRS SC Hollow)

Discussion in 'Luthier's Guitar & Bass Technical Discussion' started by jads57, Sep 20, 2008.

  1. jads57

    jads57 Supporting Member

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    Hi, When I turn the volume knob even a little down, I`m suffering pretty drastic treble loss. Any one have a cure, it`s just a master volume and tone w/ 2 PRS Archtop p/ups. Thanks in advance!
     
  2. David Collins

    David Collins Member

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    Add the typical treble bleed. The most effective arrangements are typically the combination of a cap (.001μf to .002μf) in parallel with a resistor (150kΩ to 220kΩ), run between the center and outer (non-grounded) lugs of the volume pot.
     
  3. jads57

    jads57 Supporting Member

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    Thanks David, I was looking at upgrade kits at RS Guitarworks. And the one they have for PRS guitars says it includes.022 guitar cap and special 500k volume and tone pots. Any thoughts on their stuff? www.rsguitarworks.com Thanks again!
     
  4. David Collins

    David Collins Member

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    Their volume pots are a custom taper with a gentler curve, a compromise about half way between a modern audio taper and a linear taper. It can indeed lessen the treble drop problem you're describing, but won't alleviate the problem entirely.

    The tone pot is a standard audio taper, and whether their caps result in a better tone or just different is entirely subjective. I'm quite happy with standard off-the-shelf ceramic or mylar caps for tone controls, but what is certain is that you won't hear any real notable difference unless you are actually using your tone control.

    I would just start with a .001μf cap / 220kΩ resistor treble bleed circuit. I'd be willing to bet that you'll be perfectly happy with it's performance with that simple mod.
     
  5. jads57

    jads57 Supporting Member

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    Thanks again for the info David.
     
  6. jads57

    jads57 Supporting Member

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    I contacted PRS , and it was suggested by them to use a 180 pf cap to rectify this problem. Is this drastically different from what David Collins has suggested already. Thanks again!
     
  7. David Collins

    David Collins Member

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    Interesting... 180pf is .00018μf - about 1/5 the .001μf capacitance I typically use with a resistor. I imagine it should probably work nicely without the parallel resistor and without notably changing the taper (though I actually like that).

    If you go this route I'd be interested to hear how it works.
     
  8. jads57

    jads57 Supporting Member

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    I`ll let you know David, thanks again!
     
  9. Rosewood

    Rosewood Member

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    I'm surprised there wasn't a 180p already on the pot. most PRS guitars have them.
     
  10. JLee

    JLee Supporting Member

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    I'm not familiar with the control layouts for PRS SCs, but if it's anything like a standard Les Paul, you could try a 50s style wiring scheme where the cap is soldered to the output(center lug) of the volume pot as opposed to the input. Had my guitars rewired by a tech to 50s wiring and couldn't figure out why I was getting treble loss until I gutted everything and started from scratch. The tech had soldered the cap to the wrong lug. Made a world of difference.
     
  11. jads57

    jads57 Supporting Member

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    Thanks again to everyone for your help! I ended up taking David Collins advice, and it`s working just fine for my needs.
     

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