Help! Adding Graphtech ghost system to single pickup bass w/Duncan 3-band pre

Discussion in 'Pickups & Electronics [BG]' started by jbo, Nov 4, 2012.

  1. jbo


    May 2, 2007
    Wichita, KS
    Hey all! As the title says, I am thinking of adding a Graphtech ghost system to my bass. The bass is a fretless 6-string with a single pickup in the bridge. I have an active Duncan Steve Bailey 3-band pre-amp onboard (which sounds very nice btw!). So my plan is this: I would like to run the piezo and mag into the TRS output jack (allowing for mono only) with both having their own volume, which is possible based on the schematics on the Graphtech website. My problem is, I want the piezo system independent of the Duncan pre, so that the only signal going through the pre is the mag pickup. Is this possible? Is it practical? I'm including the links to the schematics of the Duncan pre and Graphtech system.

    Duncan (ignore the neck volume):


    If I have this right, could I just connect the hot output from the duncan to the green wire labeled 'mag' on the Graphtech??

    Looking through the Graphtech site, I just found this schematic which has an active pre wired in:

    Isn't that what I'm trying to do?

    Thanks for your replies and help with this!! Just want some clarification before I take the plunge with all this.

  2. Rayz28


    Sep 5, 2011
    Any updates on your build? I'm considering something similar.
  3. This is a super old thread, but, what kind of piezo buffer do you have? Wiring will depend on that.

    If there is an input for magnetic pickups, then the Seymour Duncan preamp's output will go there. Otherwise, you will sum the Seymour Duncan preamp and piezo buffer together at the jack. (After going into volume pots.)