Wire Pickups Directly to Jack, with Half Tone??

Discussion in 'Luthier's Corner' started by MonsterTruck88, Jul 23, 2009.

  1. MonsterTruck88


    Sep 4, 2008
    I'm working on a custom P-bass project, and I want to wire the pickups directly to the jack. As I understand it, this would be equal to full volume, and full tone. However, I only want half tone (as though the tone knob was rolled to 50%). Is this possible?? If so, how would one do it??

  2. Ric5

    Ric5 Supporting Member

    Jan 29, 2008
    I like 5, 8, 10, and 12 string basses
    Try 1000k ohm pots. When tou turn them to 10 you get the wide open sound.

    However you may find the tone harsh on a p-bass.
  3. msiner


    Sep 2, 2008
    Tucson, AZ
    If it were me, I would measure the resistance of the pot at "half" with a multimeter. Then buy a resistor to match that value and wire it in to the circuit in place of the tone pot. I have never tried that, but, in theory, I believe it should work because the pot is a variable resistor and you want it set to a specific value. Another option might be to wire the pot in, but leave it in the control cavity with no knob. That way you can set it to the value you want, but can take the pickguard/control plate off to tweak it if you are wanting a different sound.
  4. use a linear (tone) pot at "half" when you measure the resistance this will get you a lot closer to 50%than an audio pot will.
  5. Stealth


    Feb 5, 2008
    Zagreb, Croatia
    By using a linear pot vs. a log pot, you'll get different resistances measured simply because of their different behavior. There's no "closer to 50%" when comparing lin/log pots - two 500k pots with different resistance curves will each be able to hit the "50% mark" - but at a different spot during their travel.

    I'd stick with measuring with whatever the OP has in right now and using THAT 50% as the mark, as msiner above said. After that, it's simply a matter of putting a common resistor with that value instead of the pot and presto, instant 50%. Naturally, the cap will have to stay connected as it was.
  6. Well ,yes yes, if you want to split hairs ;)

    damn kids and their linear pots
  7. Or simply get one of these Sub-Miniature Fully Enclosed Carbon Preset Potentiometers


    No need to measure resistance, no need to be absolutely stuck with the tone that one fixed resistor would give. Just tweak it to taste and leave it in the control cavity doing it's thing. You can always tweak it again if you want to fine tune your tone
  8. When you roll the tone pot down what you're doing is bring the capacitor into play, not a resistance. The cap is what rolls off the highs.

    Simply place a cap of the appropriate value in parallel with the output.

    This might not work! You'll have to experiment a bit.
  9. OMG your a genius.I'm going to go buy like 30 of those.
  10. Stealth


    Feb 5, 2008
    Zagreb, Croatia
    Of course the cap's what rolls the highs, but you need to have a resistor in series as well. A low-pass filter isn't an RC-network for nothing, you know. :smug: When you turn the tone pot, you're acting on the resistance while the capacitance stays the same, right?

    Jools4001 - that may as well be the best solution yet. Set and forget until you regret. :D

    *prepares for pun hell*
  11. Of course. Just wanted to make sure it was clear that just adding a resistor won't do anything. As you say you need both the R and the C :D
  12. vintager


    Jan 29, 2005
    i personally wouldnt run my signal through component like carbon mini pot but chose an audio grade fixed value cap.