Upgrading Pots

Discussion in 'Pickups & Electronics [BG]' started by SplinteredSkull, Feb 9, 2014.

  1. I'm planning to upgrade the pots and the capacitor in the P/J bass I built with something not cheap and no name. Right now I'm thinking just a .047 Orange Drop cap, (2) CTS 250K volume pots, and (1) CTS 250K No-Load tone pot, all audio taper. My main question is in deciding between 250K pots and 500K pots. From reading on TB I think it's my understanding that the 500s will be brighter and have more high frequencies coming through and the 250s will be darker. Does this simply mean that the top end will be more open, and if I don't like the highs coming through I can just turn down the tone? I've also read it's better to get linear taper with 500K pots, and that a no-load tone with 500K is pointless. Can anyone provide some :help: ?
  2. Any particular reason you want to change pots? It's usually only worthwhile if there is a taper issue, mechanical problems, or a desire for different values.

    Put me in the linear taper camp. That's the way to go for basses. Be sure you use an audio taper tone control, however.
  3. AlarmClock314


    Mar 26, 2007
    Southern WI
    In my experience, higher total ohmage increases the treble response on a bass. This can be desirable if you want a 'zingier' tone overall or if your bass is too dark naturally. A quick and easy way to estimate the difference between a 250k pot and a 500k pot is to set the volume of a 250k pot to 5 (play and listen), then to 10 (matching volume on the amp, play and listen), then projecting what it would sound like set to 15.

    A popular upgrade for VVT basses is to use two 250k linear taper volume pots a with a 500k audio taper tone pot. This (in theory) changes the total ohmage from 83.3k to 100k, making for a slightly brighter tone. The tone knob can still be used to darken the sound as needed.

    Do some additional research on Talkbass. There are lots of topics about pot ohmage and pot taper.
  4. It was a kit bass that actually sounded surprisingly good. All the electronics in it were pretty cheap. The pots are slightly scratchy sometimes and I have no idea what's in there except the pots are all 500K

    EDIT: There was also a hiss when I initially put it together. I just assumed this was a grounding issue because of a quick put-together. However, it did disappear if I turned down the tone knob
  5. So my the bass seems naturally bright, and it has 500K pots. Would switching out the volumes for 250K and leaving the tone at 500K theoretically make it more or less bright?
  6. GlennW


    Sep 6, 2006
    I'd try a bigger cap, and use the 500K pots.

    Ime, 250K are tone suckers in basses.

    You can alligator clip another cap across the legs of your current cap to get an idea of how it will sound, since cap values add when in parallel.
  7. After just reading more I think I will stick with 500K pots. I like the open top range of it. And I have no idea, but the cap very well could be a standard .022. So the .047 might help tame it a little.
  8. And I see there is much debate on this, but I'll try out linear taper for the volumes and audio taper for the tone.
  9. AlarmClock314


    Mar 26, 2007
    Southern WI
    Yep, a lot of it is personal preference and bass dependant. I think that is a good route to take though. Good quality pots are pretty inexpensive, so don't be afraid to experiment and find what you like. You can also use an ohm meter to measure the exact resistance of a pot.
  10. Much thanks guys!