Potentiometer values and tone

Discussion in 'The Pickup Place' started by swivel, Sep 10, 2019.

  1. swivel

    swivel Synchromatic

    866
    May 13, 2018
    PNW
    Ok, maybe I'm having a brain fart, but I got very confused on this yesterday. Just trying to confirm what I thought I knew!
    -A higher value Volume pot produces brighter tone/top end. So 500k more bright than 250k.

    -A higher value Tone pot produces brighter tone/top end. So 500k more bright than 250k.

    - A smaller value capacitor on the tone pot allows you to hear more low end freq's. or does it just cut more high freq's? So a .022 uf cap will let you hear more low end than say a .10 uf??
     
    MTurner likes this.
  2. MTurner

    MTurner Friend of Fred

    Age:
    63
    Aug 17, 2010
    Clayton, North Carolina, USA
    I am comforted to know that I am not the only one here for whom this stuff is not second nature.
     
    JHowdy likes this.
  3. swivel

    swivel Synchromatic

    866
    May 13, 2018
    PNW
    Wait! I think I got the last part wrong! A .1 uf cap will let you hear more lows right? :mad:
     
  4. swivel

    swivel Synchromatic

    866
    May 13, 2018
    PNW
    OK, never mind, I got confused yesterday by googling and there was a confusing statement by one of the pickup makers: "Tone capacitors are wired to the tone pot so the signal from the guitar pickup will pass high frequencies to ground when the tone pot is rolled down. The higher the value of the cap the wider the range of frequencies that get rolled off to ground. " That last part is confusing, because 'wider range' to me meant including some of the lower freq's. What Lollar means is 'wider range of highs'.

    I think this is correct:
    The lower the pot value the darker the tone, hence a single coil uses a 250K to tame the shrillness it can reach, humbuckers need 500K to keep from being to dark and muddy unless they are very bright to begin with.

    Cap values depend on what kind of tone you want, the smaller the number, the less highs it rolls off as you turn the tone knob from 10 to 1.

    A .047 will roll off the highs much earlier than a .022, a lot of guys on humbuckers use a .015 or .01 on their neck pup so they can roll the tone back and it doesnt turn to mud. It all depends on what sound you the user wants,, factories or guitar companies just stick with the standard rule of thumb when sending out the door.

    So here's the problem, with a higher value cap, which should cut the brittle highs, the taper may be too fast and you cant get where you want to be. With a high enough value cap, now the pot is almost acting like a switch with a rapid transition from bright to mud.
     
    Last edited: Sep 10, 2019
    section2, j.s.c and MTurner like this.
  5. Floo

    Floo Country Gent

    Dec 16, 2012
    Elmshorn, Germany
    A higher value cap will also cut off lower frequency treble. I can't tell in Hz, but a big cap will even go into high-mid frequencies. If you just want to tame some brightness, a 250k pot and a .015 cap will do the trick: the pot will pass some brightness to ground anyway (even a 250k volume pot sounds a bit darker than a 500k), and it will react a bit earlier than a 500k pot when turning it down, so the cap will start working - passing high freq to ground - earlier on it's rotation.
     
    swivel likes this.
  6. swivel

    swivel Synchromatic

    866
    May 13, 2018
    PNW
    Thanks. Yeah, I have the opposite problem, a Hollow Tele type with P90's that is surprisingly warm sounding with the tone pot dimed. It has 500k pots in it, but I'm not sure what cap is on the tone pot. I may put a no load tone pot in to bypass the tone circuit entirely.
     
    section2 likes this.
  7. hcsterg

    hcsterg Country Gent

    Feb 13, 2012
    France
    1 - Use LOG (A taper) pots for Master Volume and Master Tone.
    2 - Use REVERSE LOG (C taper) fror Pickup Volumes in the classic Gretsch wiring (not Gibson).

    Doing this, you'll have all the progressivity in adjustment you expect... ;)

    A+!
     
    Bertotti and j.s.c like this.
  8. Charging Charlie

    Charging Charlie Gretschie

    103
    Jun 21, 2018
    Maryland
    The cap should not matter if you have the tone knob all the way up.It is possible that you have a bad tone pot. Does the tone change at all when you roll the tone knob off ?
    Charlie
     
  9. swivel

    swivel Synchromatic

    866
    May 13, 2018
    PNW
    Yes, tone rolls down and gets warmer. I think it's just a warm guitar. It's a carved/arched top solid wood Tele shape. Originally I thought it was the P90's then I got Gibson P90's and it's the same! I'm used to P90's be clean with an edge of grit, but not warm! I'll have to test that pot and see what the sweep looks like I guess.
     
    Charging Charlie likes this.
  10. j.s.c

    j.s.c Country Gent

    Aug 19, 2008
    france
    From my personal experience, few points on this topic :
    1-Mastervol count more than individual vol... I don't know why... perhaps they weight more because they're leaking and the end of the wiring in a kind of chain reactions.

    2- Ohmage of volume pots has more impact than pots (which are close to be unsensitive to ohmage to my ears... but I know people don't agree with that). Btw the lower the tone pot value is, the smoother is the taper response.

    3-We're talking of bright tones here but also of global output volume (more volume <=> more trebles in the mix). Of course, the less pots you have the higher is your output (and brightness).

    4-Some pickups are more sensitive than others... dyna are sensitive to these changes, filters also but less. Single coils have stronger reactions than humbuckers and I presume, the more resistance you have the more your pickup the more it will be sensitive.

    Let's sum-up in one word : #blackmagic
     
  11. section2

    section2 Country Gent

    Dec 21, 2016
    Toronto
    No-load tone pots are a good idea. Normal tone pots will darken your tone even when they're turned all the way up, simply because the pots themselves add to the load regardless of whether the caps are engaged. No-load tone pots will remove themselves from the circuit entirely when they're dimed. You can also try higher-value volume pots if you want to go farther down that road.
     
    swivel likes this.
  12. Charging Charlie

    Charging Charlie Gretschie

    103
    Jun 21, 2018
    Maryland
    Have you checked the pickup heights ?
    I raised the pickups on my 6119 and brightened the tone noticeably.
     
  13. DHart

    DHart Gretschie

    254
    Jun 26, 2019
    Arizona
    You can buy some tested pots which will be guaranteed to be, say 550k, +/- 5%.

    Pots quite often test out to be a lower resistance than they are "stated" to be.

    Sometimes when you buy a 500k nominal pot, it will test out to be as low as 420k or so. Same with 250k pots, some test out as low as 210k or so. Your 500k pots may actually test out to be more like 420k-440k-ish.

    As for the tone pots, if I were you I would buy 500k "No-Load" tone pots. That way, when the pot is dimed, it is taken completely out of the circuit - freeing more highs to be heard.

    And the cap - I like .015, even with single coils. The lower the resistance of the cap - the highs that are reduced when engaged are only of the highest frequencies. So, a .015 cap may reduce the top 5% of highs, a .022 cap may reduce the top 7% of highs, and a .047uF cap may reduce the top 10% of highs. With a higher cap, you reduce a larger frequency range of highs.

    I like the .015uF caps because on the rare occasion when I DO engage a tone pot (pretty much NEVER with the neck pickup) I only want the very highest treble frequencies reduced somewhat - I don't want a large range of high frequencies to be cut.

    Note also that tone caps do not take effect on your tone unless you begin to roll off the tone pot. With a tone pot dimed (especially a no-load tone pot) the tone pot and the cap are removed from the circuit - allowing all the high frequencies (that are available from the pickup and volume pot) to be heard.
     
    Last edited: Sep 10, 2019
  14. Ricochet

    Ricochet I Bleed Orange

    Nov 13, 2009
    Monkey Island
    What may help is to realise it's a passive circuit. You can't add/boost stuff. Only remove, or roll off. So if the tone is too gritty and warm, maybe you don't want to roll off more or less treble, but bass instead. Maybe...
     
  15. stevo

    stevo Country Gent

    May 1, 2012
    Atlanta
    Higher value pots put a higher reactive load on the circuit - doesn't matter which pot they are.

    Tone caps are passing frequencies to ground like a shelf. Higher value caps pass a wider range of frequencies to ground, lower value a narrower range.
     
  16. swivel

    swivel Synchromatic

    866
    May 13, 2018
    PNW
    Good info thanks. I have to disagree a bit on " a tone pot, dimed, ...." My experience is it does sound different with it in than taking it out completely, been there done that!
    I have a ton of guitar 500k pots around I'll just test some, but I will be going to a no load for the tone also. We'll see how that works out this time!
     
  17. DHart

    DHart Gretschie

    254
    Jun 26, 2019
    Arizona
    You’re welcome. No disagreement, anything in the circuit has a slight effect, which some may or may not hear. The tone cap, when the tone pot is dimed, is inaudible.
     
  18. hcsterg

    hcsterg Country Gent

    Feb 13, 2012
    France
    Yes. The pot can be considered then as a simple resistor in // on the pickups (the Z of the cap being negligible in comparison), and this resistor affects the damping of the pickup and thus its resonant frequency and peak amplitude ( = decrease). It's neatly audible with 500K to 250K value shift and morover for lower values.

    A+!
     
    Last edited: Sep 12, 2019
    DHart likes this.
  19. swivel

    swivel Synchromatic

    866
    May 13, 2018
    PNW
    Just an update to close this out:
    I replaced the tone pot with a no load 500k. Used a .018 capacitor on it. I also put a treble bleed on this guitar (although I usually dont like them) Things are great now! Plenty clean and got rid of the mush.
     
    Henry, section2 and DHart like this.
  20. DHart

    DHart Gretschie

    254
    Jun 26, 2019
    Arizona
    Way to go, man! Glad you massaged that guitar into a sweet spot for you.

    I'm like you, if a guitar isn't absolutely thrilling me with the tones... I take it into the O.R. and make it as I want it to be. Or, it gets gone.

    There is much that can be done to tweak the tones of an electric guitar to your idea of perfection, whatever that is.

    I just Gretsch-ified my Gibson ES-339, a guitar I rarely played and considered selling, as PAF humbuckers just weren't floating my boat any longer. Now, with TV Jones TV-HT pickups in it, 530k pots and a 530k No-Load tone pot on the neck pickup - with 50's wiring, I've got tonal nirvana with this ES-339.
     
    section2 and swivel like this.
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