Pots cut out at 10

Discussion in 'Pickups & Electronics [BG]' started by HardPuncher, Jan 10, 2014.

  1. HardPuncher


    Jul 14, 2013
    Hi guys,

    Just finished my second-ever rewire today, and ended up having exactly the same problem that I had last time: my pots all cut out at the maximum setting.

    To make matters worse, the tone control seems to be acting like a Master volume, instead of a tone control.

    Any ideas? Both basses are passive, and have an extra ground wire which connects a copper plate below each pup to the pot chassis. One is a Tokai PJ bass, the other is a Tokai Jazz. Both are wired with three 500k audio taper pots, with a single 0.47 cap on the tone pot.

    I'm willing to accept that I've somehow burned out 6 pots, but it seems weird that they'd all only be burned out at maximum...
  2. You'll need to post pics and/or a diagram of what you did.

    It is possible that the wipers are going beyond the resistive track at the extremes of the rotation. This would disconnect the pickups from the output.

    When tone controls behave as volume pots, a number of things may be to blame. A shorted or leaking capacitor can cause the pot to control output impedance for all frequencies. If you are off by an order of magnitude in your capacitance selection, the frequency cutoff can be shifted, causing the same issue.
  3. antonspon


    Mar 27, 2013
    The tone pot behaving as a master volume is a problem I've come across in my Gretsch and my Squier VM Jazz: the problem appears to be that the tone pot is positioned in circuit *after* the volume controls, unlike Gibsons, Ricks, etc. At full volume the tone works fine, but if you turn down a notch, the tone control's impedance affects output volume.

    My solution in both cases was to replace the tone pot with a dual-gang pot: effectively each pickup has a separate tone, positioned ahead of the volumes, with a single control knob (still a master tone control, although a dual-concentric pot would give you individual tone controls in the same space).
  4. How well did that work out? When both volumes are up, you should see an increased total capacitance. The effect of each control on the output varies as the volumes are adjusted, as you have varying degrees of isolation. Or did you only use one capacitor?
  5. antonspon


    Mar 27, 2013
    It works much better than the standard master tone pot (no pseudo-volume effect), but as with any passive bass, of course there is some loss of highs at lower volume settings. I used a separate cap for each tone (0.022mF for the neck and 0.047 - just my preference).