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250k vs.500k pots and .22 vs. .47 caps

Discussion in 'Pickups & Electronics [BG]' started by SX lover, May 3, 2010.

  1. SX lover

    SX lover

    Jun 14, 2009
    Hey gang. I just installed a set of Bartolini 8S's in my SX P-bass,along with 250k CTS pots,and a .47 orange drop cap.(it came from SX factory with a "black-block" maple neck.) The p-ups sound "unreal"! Very clear,spacious,3-D,deep,powerfull...etc. I'm on the verge of building another SX P-bass,with the same Bartolini 8S's(fretless neck,P-J p-ups...)and was wondering if i installed the 500k pots&.22cap(instead of the 250k pots&.47 cap...)would the tone of that bass become much more "trebley",than "midrangy"?? And would the bass become more "midrangy"...insted of the "deep,powerful lows"?? Your opinons,please. Thanks!
  2. RedLeg

    RedLeg Supporting Member

    Jan 24, 2009
    Kaiserslautern, Germany
    Nov Shmoz Ka Pop?
    500k's make fore a brighter sound. I cannot comment on the cap.
  3. Bassamatic

    Bassamatic keepin' the beat since the 60's Supporting Member

    The pot and cap will allow more highs to pass, but will not affect the bass and mids.

    However, the 8S does not have a lot of highs, so you will probably not notice anything.
  4. 500K/0.022uF (BTW, you're missing a zero in your cap values. 0.022uF or 22nF and 0.047uF or 47nF) should be brighter than 250K/0.047uF, but it won't be a huge difference. It will be somewhat subtle, but IMO, definitely noticeable difference.

    The bass response will not change btw.
  5. PSPookie


    Aug 13, 2006
    Lubbock, TX
    The pot will make a bigger difference than the cap. IMO/IME .0.022uF caps don't sound much different than 0.047uF caps in a bass application. Plus, when the tone knob is full on (10) you are basically bypassing the cap. The higher resistance pot further reduces bleed thereby minimizing the cap's effect on overall tone. FWIW, I like a 0.1uF cap.
  6. Are you kidding?

    I tried a 0.022uF cap once, and I thought it was pretty much useless.
    I had to roll the tone knob way down to get the same tone I got with a 0.047uF cap and the tone only turned down a little bit.

    Huge difference.
  7. PSPookie


    Aug 13, 2006
    Lubbock, TX
    I can see that. I don't usually use the whole range of a 0.047 cap since I don't like how they sound after you turn them down more than half way. So I guess 0.022 rolled all the way off is robably roughly equivalent to a0.047 turned down half way.

    I tend to agree that 0.022s are pretty much useless for bass.

  8. flewis

    flewis Gold Supporting Member

    Mar 3, 2006
    Raleigh, NC
    I'm curious about the 500k Pot change. Are we referring to swapping out both vol pots and tone pot from 250K to 500k or just the vol pots, or just the tone pot?
  9. Volume pots have a greater effect than tone pots as far as values go.

    Unlike volume controls, A 500K tone control set to 250K is identical to a 250K tone set on full. This just means that the end of the pot rotation is a bit brighter than a 250K pot.
  10. darkstorm


    Oct 13, 2009
    I like 250k pots better myself. 500k pots are more trebly then I prefer and can impart a harshness to the treble in some cases. 250's give fuller more balanced sound lows thru highs and smoother treble to me.
  11. guroove


    Oct 13, 2009
    Buffalo, NY
    I find this subject interesting, because I've been tweaking the sound on my P-bass since I got it. Would the treble imparted by a change in pots be harsher, brittle sounding, or would you call it sizzle? I've always loved the way a P-pickup growls and sizzles on glisses and slides. I've got flatwounds on my P. Do you think 500k pots would be wasted on my particular application?
  12. SGD Lutherie

    SGD Lutherie Banned Commercial User

    Aug 21, 2008
    Bloomfield, NJ
    Owner, SGD Music Products
    I have a 0.022µF cap in one of my basses. I like to use them when I want the tone control to remove the treble, but not the mids. It also gets a cool resonant peak thing going on. The larger the value, the lower in frequency the cut, so a .1µ will remove frequencies starting lower than a .047 or .02.

    Of course it all depends on the pickups it's being used with, since they form a resonant system.
  13. walterw

    walterw Supportive Fender Gold Supporting Member Commercial User

    Feb 20, 2009
    that's the key. one man's "sizzle" is another man's "harsh".

    i love the brighter "unloaded" tone of 500ks on fender basses. to me, it makes the bass's character come through in the mix of the whole band; you really hear "P-bass" or "J neck pickup" or "J both pickups" rather than just "bass guitar". even with flats, you'll get a more percussive attack.

    also, if it's too bright, that's why they invented tone knobs.

    the thing is, i play rock with a slightly compressed and grindy sansamp tone into cabs with no horns. someone else with a different style, rig, and gig might not like that sound.
  14. SGD Lutherie

    SGD Lutherie Banned Commercial User

    Aug 21, 2008
    Bloomfield, NJ
    Owner, SGD Music Products
    Exactly, and one person's "dark" is someone else's "vintage" or "organic".

    I agree 100%. I love the tone of flats with a lot of highs. That really is the old school tone, even though these days players think it's all about just low end. If you listen to solo motown bass tracks, the tone is wide open with a nice click on the top.

    And sometimes that's the only way to get a certain tone... with the tone control off.

    I play with a very clean amp tone, 1X15", 1X10" and a horn, and then use a BlueTube pedal with a 12AU7 for some grind. One bass has half rounds and the other has rounds, but I keep the signal bright for both, and use the tone controls when I want a darker tone.
  15. DavePlaysBass

    DavePlaysBass Supporting Member

    Mar 31, 2004
    Or you could wire with 250K no load pots.

    250Ks will blend different than 500Ks. 500Ks are more like on / off switches where as the 250Ks volume / volume gives a more uniform blend.

    And then the no load pots allow you to switch all the 250K loading resistance out of the circuit when you want to go wide open.
  16. walterw

    walterw Supportive Fender Gold Supporting Member Commercial User

    Feb 20, 2009
    yes, unless you use linear volume pots, which even if they're 500k will sweep and blend more evenly than audio tapers. (stick with audio for the tone pots.)
  17. DavePlaysBass

    DavePlaysBass Supporting Member

    Mar 31, 2004
    Its not the taper, its the actual resistor divider created by the pots. A 250K pot has a resistor divider where the two halves always add up to 250K. A 500K pot has a resistor divider where two havles always add up to 500K. As you sweep thru the range, the difference in resistance values react differently with the pickups which themselves have measureable impedance.
  18. And that depends a lot on whether the wiper terminal is wired to the pickup or the output.

    If you have the wiper terminal wired to the output, the load against the pickup is constant.
    If the wiper is wired to the pickup OTOH, the resistive load against the pickup varies from 0 ohms at "0", to 250K ohms at the center of the pot's resistance, to 1/(0.000002+[1/output impedance]) at "10".
  19. Silent Fly

    Silent Fly Commercial User

    May 8, 2006
    London - UK
    Owner/designer [sfx]

    I love the 22nF cap on my Fender JB. I have a push-pull on the tone knob to change it to 47n but I always keep it set to 22n.
  20. dannybuoy


    Aug 3, 2005
    I've been thinking of doing the same to my P-Bass Max, and I think you may have just convinced me!

    My P-Bass has a push button S1 switch on the volume control, which I previously rewired for volume/tone bypass, hooking the pickup straight to the output jack which gives it a bit more zing. I should be able to swap them around so I have a push button tone pot instead... Anyone know if the vol/tone pots in a 2005 USA Precision have the same taper? Guess I'll find out next time I take it apart. I was gonna copper shield that bad boy and put a Duncan SPB-1 or Fralin in there too while I'm at it!

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