Choosing a Tone Capacitor and Pot

Discussion in 'Pickups & Electronics [BG]' started by JeffJ2112, May 13, 2019.

  1. JeffJ2112


    Apr 17, 2016
    Nowhere Indiana
    What do I need to know?

    I'm looking at converting a bass that comes with a two band pre to a passive.

    Easy to do for a novice at soldering or should I leave it to a pro?

  2. Gravedigger Dav

    Gravedigger Dav Gold Supporting Member

    Mar 13, 2014
    Springtown, Texas
    ihaveaquestion, DavC and JeffJ2112 like this.
  3. Gravedigger Dav

    Gravedigger Dav Gold Supporting Member

    Mar 13, 2014
    Springtown, Texas
    But seriously, folks, soldering isn't that hard. it takes a little practice. Watch some videos and practice on some junk pieces. Also, be sure the connections are wired correctly. Good luck.
    JeffJ2112 likes this.
  4. Is your question about which pot and cap to use or how to solder?
    Title and body of post are two different subjects...
    JeffJ2112 likes this.
  5. sikamikanico


    Mar 17, 2004
    It may be just a matter of disconnecting the preamp. Show a pic of what you got?
  6. Well, first you should know that adding a passive bypass switch plus a passive tone control are both pretty common mods, so there's a good chance you could have your preamp cake, and eat your passive tone control too.

    But if you want to remove the pre, and go fully passive, that's totally cool. The first thing to do is look at the existing volume and/or blend pots and see if you can keep them. If they are 250k or 500k, you should be able to simply remove the pre, then find the wire that went from the volume pot to the preamp input, and re-route it to the jack. Then run a simple passive tone control from the blend pot or volume pot.
    JeffJ2112 likes this.
  7. sissy kathy

    sissy kathy Back to Bass-ics Gold Supporting Member

    Apr 21, 2014
    Arbutus, MD
    The first thing you should do is determine whether you have active or passive pickups. If they are active you are going to replace everything under the pickguard. Otherwise see post #6 above, it's a start.

    To answer your question directly, select the pots you want to use 500K pots are a little brighter than 250s. That's because the 250 lets some highs leak to ground whether you want them to or not. Second how much treble cut do you want? If you like things on the bright side then a smaller value like a 22 micro farad cap will do you. If you want some thump in there use a higher value cap a 47 is pretty extreme but some use them. To sum up 500k pots and small cap value, bright sound, lotta highs; 250k pots and large cap, thump verging on mud.

    Use the same value of pot for the vol and the tone. I use 500K pots to keep things as as bright as possible when the treble cut is off, and a substantial cap to kill all that treble when I want thump.

    Since you are trying to lose the active electrics, you probably have some extra holes you need to fill. You might want to look into a varitone type control. then you can not only control the volume of treble cut, you can also control the cut frequency.
    Last edited: May 13, 2019
    HeavyJazz and JeffJ2112 like this.
  8. JeffJ2112


    Apr 17, 2016
    Nowhere Indiana
    Both actually. Seems like it would be pretty simple looking at it though.
  9. CallMeAl


    Dec 2, 2016
    Ithaca Ny
    The pots have been covered ad nauseam on TB and WWW, so I'll skip that.

    But soldering, I vote do it! I've recently started doing my own. My first job was a little sloppy, but even then the bass still works. It is very satisfying, interesting and enlightening to know how your bass works, how to replace parts, and test out new components.