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Thread: Pot-resistor trick.

  1. #1
    Overlord of Music fender3x's Avatar
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    Pot-resistor trick.

    I have been trying to figure out what pots to use with GFS Lil'Punchers. Some folks recommend using 500K pots. Others recommend using 250K pots... I thought I could wire them up using 500k pots, and then run a resistor across the two outside legs to simulate a 250K pot to hear the difference. There are lots of references to this on the internet like this one...

    https://www.fralinpickups.com/2018/1...n-guitars-101/

    ... Sometimes when you see this discussed the author will say that, while this will work with the pot all the way open, it will also mess with the "curve" on an audio or linear pot. But how does it change the curve? After much searching, I still did not find anything, so I decided to do my own test.

    Click image for larger version. 

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    The scale on the left is in K-ohms. Orange line is a 500K linear pot with a 470K resistor across the outside legs. Blue line is a 500K audio pot with a 470K resistor. The gray line is an unaltered 250K audio pot.

    As you can see, the resistor gives the 500K pots just about exactly the right value... (243K and 244K). The unaltered pot (CTS A) is slightly hotter at 260K. I took readings at open, 3 o'clock, 12 o'clock, 9 o'clock and closed, each represented by a "dot" on the chart.

    Interestingly on both altered pots, basically NOTHING happens for about the first quarter turn, whereas for the unaltered pot, there is a pretty big jump. After that, the linear pot behaves almost linear, the unaltered pot behaves like an audio pot, and the altered audio pot is sort of in between.

    Not sure what to make of this, but thought it was interesting enough to post. Looks to me like this is probably a viable approach to altering the pot, particularly if you want linear...or something in-between audio and linear--AND you don't mind that you won't hear any change in the first quarter turn (at least).

  2. #2
    Overlord of Music McCreed's Avatar
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    Thanks for posting your results. It's good to have hard data to reference for these kinds of things.

    FWIW, I've seen 300k pots used for that "middle ground" value. Some like them when using a humbucker/single coil combined guitars.
    They're readily available (especially in your part of the world).
    Making the world a better place; one guitar at a time...

  3. #3
    Overlord of Music fender3x's Avatar
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    Sounds like a value to try. I have a bunch of resistors ;-)

    Sent from my ONEPLUS A3000 using Tapatalk

  4. #4
    Mentor JimC's Avatar
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    I have a HSH Strat wired with an across the pot resistor, but switched so that the volume pot is 500K with pure humbuckers, and ~250K when one or other coil tap is engaged.

  5. #5
    Overlord of Music fender3x's Avatar
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    That sounds like a great use of this sort of mod.

    Sent from my ONEPLUS A3000 using Tapatalk

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