Looking for a wiring diagram for Active/Passive switch.

Discussion in 'Pickups & Electronics [BG]' started by MrLenny1, Jun 20, 2020.

  1. MrLenny1


    Jan 17, 2009
    New England
    Anyone have a diagram for an Active/passive switch?
    I tried 2 different ways and not working properly.
    1.) Put Switch on the battery negative. Active works,get a popping sound when switched to passive then no output in passive .
    2.) Switched the Volume control and pre-amp circuit, works but battery drains with
    no input cable. Arggh.
    Any help would be appreciated.
  2. skycruiser


    Jan 15, 2019
    I think this is a typical wiring design:


    The socket for the output audio cable should connect/disconnect the battery ground, so it turns off power to the circuit when you disconnect the cable.

    If you can fit a 3-pole switch in this design, you might consider having the passive/active switch also switch the battery power to the circuit board. With this design, the active circuits will continue to draw power even in passive mode.

    I'm not sure how passive tone controls fit into this design. If they connect to the "output to jack" signal then they will be in circuit in both active and passive mode.
    Last Rebel and Low Commotion like this.
  3. MrLenny1


    Jan 17, 2009
    New England

    Thanks, I'll try that.
  4. Last Rebel

    Last Rebel Lone Wolf - No Club Supporting Member

    Mar 11, 2011
    Ontario Canada
    Once again ... TB members come through ;)
  5. Low Commotion

    Low Commotion Supporting Member

    That’s the one that I've used too
  6. walterw

    walterw Supportive Fender Commercial User

    Feb 20, 2009
    ehh, that's the "old" TB switching, it's not so good. when bypassed it leaves the preamp input floating, causing noise, maybe even oscillation and popping.

    here's the one you want, it's what all modern TB pedals use:


    "effect send" goes into preamp input, "effect return" comes from preamp output, "input" is from the pickups and volume controls and "output" goes to the jack.

    when in bypass it shorts the preamp's input to ground, silencing it internally while it isn't being used.
    you might be misunderstanding how this works: you don't shut off the battery in any case, in passive mode the battery is still draining while the cable is plugged into the instrument.

    trying to de-power the battery in passive mode leads to loud ugly power-up noises, that's why it's not done.
    Low Commotion and skycruiser like this.
  7. MrLenny1


    Jan 17, 2009
    New England
    Thanks to all for your input. Going to try this tonight.
    I got the bass used and the active/passive switch had been removed
    and I'm trying to get it back to original state.
    Talk Bass is THE place.
  8. MrLenny1


    Jan 17, 2009
    New England
    I started with walterw's diagram and it works great but
    I'm getting noise when using a wireless & switch in Active.
    With just a cable it is very quiet.
    I'll double check my grounds to correct the issue with my wireless.
    Once again thanks TB members.
  9. MonetBass

    MonetBass ♪ Just listen ♫ Supporting Member

    Sep 15, 2006
    What is your volume pot value? If it's 250K, you'll need to replace it with a 500K pot to keep the volume consistent when you bypass the preamp.