P-bass pot help - 500k

Discussion in 'Pickups & Electronics [BG]' started by pocketgroove, Nov 3, 2012.


  1. pocketgroove

    pocketgroove

    Joined:
    Jun 28, 2010
    Location:
    Detroit
    Please help...I'm at my wit's end. I just got a new Lollar pickup and was planning on doing a complete rewire, including new, high-quality 500k pots. I don't need anything fancy, but I can't seem to find anything at all. The local GC had some of their Proline ones to offer, but they were junky and at $5 a piece I had to pass.

    Can someone please direct me to a specific site or link or something with nice quality 500k pots of the appropriate size to fit in a P bass? I would appreciate it immensely...I've found several potential options, but then it turns out that the size is wrong, as they're for guitar instead of bass. Thanks in advance.
  2. line6man

    line6man

    Joined:
    Jun 20, 2008
    Location:
    Close to Los Angeles, CA
    There is no such thing as "guitar pots" and "bass pots." Same component, same application. In any case, you must first identify the size you need. Perhaps the taper, as well.
  3. pocketgroove

    pocketgroove

    Joined:
    Jun 28, 2010
    Location:
    Detroit
    Well, I have no idea...I just need the size that will fit in a typical P bass. That's why I'm asking for help.
  4. SurferJoe46

    SurferJoe46

    Joined:
    Feb 22, 2010
    Location:
    The Bitterroot Mounts, Montana
    The 'taper' is not to get it to fit into a slanted place - it's electronics-speak for the type of resistance it has.

    Kinda like parabolic verses linear.

    Standard large pots should fit - even some from Radio Shack - although there are a few scoffers and trollish people who will mock that idea to no end.

    Get a good brand - either in a mini- or a standard shell size and then make sure the shafts is the right configuration and if it's split or solid and a few other things.

    Best yet - match up what you currently have.

    And a mini is no less quality nor is it substandard to a standard sized pot.

    This begs another question though: do you like a brighter, more modern sound or lower thumps and less clarity?

    There's a school of ideas that a 500kΩ v a 250kΩ makes the voice a little brassier and less boom-y.

    Just a thought.
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  6. walterw

    walterw Supportive Fender Gold Supporting Member

    Joined:
    Feb 20, 2009
    either way, allparts has good CTS 500k pots; you'll want linear taper for the volume and audio taper for the tone.

    they'll be more aggressive and grindy vs 250ks, but a slight rollback of the tone knob will put you back in vintage territory.
  7. line6man

    line6man

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    Jun 20, 2008
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    Parabolic? If we assume f(x)=x[SUP]2[/SUP], negative values of x will produce y-value outputs. This implies negative resistance is possible along the sweep of the pot. Negative resistance does exist (See http://en.wikipedia.org/wiki/Negative_resistance), but not as any discrete real-world component. The correct term is logarithmic. Pots come in forward and reverse logarithmic tapers, or more commonly, for manufacturing and cost concerns, approximations of logarithmic tapers which are made up of two linear segments joined to create a psuedo-logarithmic taper.

    But that's just semantics.:hyper:
  8. BGF

    BGF

    Joined:
    Aug 30, 2012
    allparts.com, stewmac.com, and guitarelectronics.com all have good quality pots.

    I agree with the linear taper for the volume and the audio taper for the tone setup suggested by walterw. That's the way I'm going to setup my Jag SS and replace the stock pots.
  9. walterw

    walterw Supportive Fender Gold Supporting Member

    Joined:
    Feb 20, 2009
    stewmac only just recently, they finally started carrying CTS instead of the cheapies they had before.
  10. pocketgroove

    pocketgroove

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    Jun 28, 2010
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    Detroit
  11. walterw

    walterw Supportive Fender Gold Supporting Member

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    Feb 20, 2009
    you widen the pickguard holes with one of these from the hardware store (called a "tapered reamer" or "hand reamer"):

    [​IMG]

    you then get knobs from say allparts as well that are made to fit USA finer-splined shafts, or just get set-screw knobs (be sure to line those up so the set screw goes into the gap in the pot so it doesn't just pinch that gap closed),

    then you drop an extra nut onto the pot before you throw the star washer on and slip it through the pickguard so it doesn't stick up too high. (any good music store with a repair guy should have extra ones that fit; hell, they should have the CTS pots, too.)

    CTS is the "typical" size for pots, and all the USA-made instruments fit them; think of all this as modding your bass to take "real" parts.
  12. line6man

    line6man

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    Jun 20, 2008
    Location:
    Close to Los Angeles, CA
    Right, it doesn't really matter if a hole is too small, in a pickguard. Just ream it to size. Conversely, it doesn't matter if a hole is too big, either. Just use larger washers and center the shaft in the hole before tightening.
  13. swsmusic

    swsmusic

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    Sep 23, 2010
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    Newnan, GA
  14. pocketgroove

    pocketgroove

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    Jun 28, 2010
    Location:
    Detroit
    Thanks so far for the help everyone. Now I'm just divided on whether I should try to find some good quality pots that are the right size to fit in as-is, or start modifying things to make the bigger size work.
  15. Ric5

    Ric5 Supporting Member

    Joined:
    Jan 29, 2008
    Location:
    Colorado
    A p-bass would normally have 250k ohm pots. 500k ohm pots would make the bass brighter. For a p-bass I would use a 250k ohm pot for volume, and if you want a warmer tone then use a 250k ohm tone pot or if you want it brighter use a 500k ohm pot. But you may not like the tone of the bass with 2 500k ohm pots.

    As per buying the pots I would go to Stewart MacDonald.
  16. walterw

    walterw Supportive Fender Gold Supporting Member

    Joined:
    Feb 20, 2009
    don't be; "good quality" pots are the size of the CTS ones you got. it's just the cheapies that are smaller.
  17. Ric5

    Ric5 Supporting Member

    Joined:
    Jan 29, 2008
    Location:
    Colorado
    Carvin makes some good quality 500k ohm smaller pots.
  18. SurferJoe46

    SurferJoe46

    Joined:
    Feb 22, 2010
    Location:
    The Bitterroot Mounts, Montana
    I stand corrected.
  19. pocketgroove

    pocketgroove

    Joined:
    Jun 28, 2010
    Location:
    Detroit
    So, the pots that I have been thinking of as large or over-sized are actually standard? I'm willing to do the modifications...does anyone have any ideas for how to make the metal knobs fit on the new pots, short of replacing them?
  20. mmbongo

    mmbongo I like turtles. Supporting Member

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    Upstate, South Carolina
    Carvin doesn't make them, they buy them from the low bidder and quadruple the price :)
  21. line6man

    line6man

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    Jun 20, 2008
    Location:
    Close to Los Angeles, CA
    If you have access to a drill press and vice, most people would just enlarge the knob's hole. Put a bit the size of the existing hole in the drill press, and use it to center the knob in a vice. Then swap the bit and start drilling. Just make sure you remove the set screw, if you have one.

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