How much diff does a 1meg tone & 250k vol pot make?

Discussion in 'Luthier's Guitar & Bass Technical Discussion' started by Shredcow, Mar 14, 2006.


  1. Shredcow

    Shredcow Member

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    Hey guys,
    I have been doing some reading and experimenting with passive electronics for my Ibanez S520EX.

    A bit of history: Everything was stock on the S520EX, H-H with 500k vol, 500k tone and 5-way switch. Now, its a 500k vol, 3-way pup selector, on/on mini toggle (coil split), on/on mini toggle (phase) and a 6-position varitone switch (from www.HAS-sound.com , great stuff). While this config gives me abt 40 different sounds, most usable, its not viable in a live situation.

    Basically, I've come to a point where I want a return to my old 5-way selector and 1 vol, 1 tone config.

    I have read on Dimarizo's website that they prefer a 250k vol pot with a 1 meg tone pot. What difference does it make as compared to a 500k vol + 500k tone pot? Aren't both configurations the same?

    Cheerio!
    Daniel
     
  2. TheArchitect

    TheArchitect Guest

    I find the volume pot to have a larger influence on the tone than the tone pot.
     
  3. John Phillips

    John Phillips Member

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    250K/1M will be smoother but clearer than 500K/500K, if that makes sense. The 250K volume will take some sharpness away compared to the 500K, but the 1M tone will give a brighter top-end when it's up full. The treble loss as you roll down the volume control will be reduced too.
     
  4. Shredcow

    Shredcow Member

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    Hmmmm.... I understand the concept of how a pot will still load a circuit even when "full-on" and how the value of the pot corresponds to that factor, i.e. The higher the value of the pot, the less the load on circuit.

    However, how does changing from 500k/500k to 250k/1meg reduce the treble loss as I roll off the volume?
     
  5. John Phillips

    John Phillips Member

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    The treble loss is caused by the capacitance of the cable, which is connected to the output of the pot, with the pickup connected to the input. With a larger pot value, as you turn down to the same point (proportionally, so the same output volume - eg '7' on the knob) there is then more resistance in series between the pickup and the cable, which makes the cable's effect greater. So even though a higher resistance pot is brighter when it's up full, it's less bright when turned down. By using a lower value pot, the tone is more consistent at different volumes.
     
  6. Shredcow

    Shredcow Member

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  7. has-sound

    has-sound Member

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    There is a circuit called a treble bleed. This compensates for the high end loss as the guitar volume pot is turned down. Stan
     
  8. rick13

    rick13 Member

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    Does the Varitone make a noise when switching between caps?
    Thanks,
    Rick
     
  9. Zero

    Zero Member

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    For which pickup does DiMarzio recommend a 250k volume pot? You're talking about their single coils and possibly their Virtual Vintage models, not humbuckers for which they recommend 500k. They even recommend 500k for single sized rail humbuckers.
     
  10. shane88

    shane88 Member

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  11. Boris Bubbanov

    Boris Bubbanov Member

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    Thanks, nice post.

    So, if a player seldom uses the tone knob and wants real full use of the volume knob, a higher value tone pot (or none at all) is the way to go.

    And if you are timid and don't want the tone control to be a total on-off type switch, you could use a 250 K volume pot and a 500 K tone pot; split the difference. Loss of high end at low volume is still reduced some.

    Hope I'm not hijacking, sorry!

    Bubbanov
     
  12. Boris Bubbanov

    Boris Bubbanov Member

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    Wait a minute. This is only gonna work if the tone pot is in series with the cable - my tone pots are not set up that way. :confused:
     

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