Carrying 9-volts up a phono cable?

Discussion in 'The Projects Forum' started by dragonrose, Oct 16, 2009.

  1. dragonrose

    Thread Starter New Member

    Oct 14, 2009
    Hi all, decided to start a few small projects all based aroudn guitars with active electronics, so for my first project im looking at the power supply.

    I've had people come to me many times wanting battery box's fitting into there guitars but its not always a quick job if it means having to get the router out and then refinish the area around the newly routed hole, so what about sending the 9v up the jack cable instead?

    I came across this on the net:

    And it looks like the same basic idea, just with more fancy features like low battery indicator, so im pretty sure i have all the materials i need right here, Heres the schematic for a guitar with active electronics:

    And now heres how i think it would be wire:

    Note i removed a pot and some non important parts so its easier to look at.

    Instead of the live wire from the EQ box going to the + of the battery clip it goes direct to the 3rd prong on the stereo jack, and then i would have a separate box like so:


    But then were does the ground of the battery go? Am i right up till this point?
    Last edited: Oct 16, 2009

    Senior Member

    Jul 1, 2008
    Your top schematic shows two grounds. One for the battery and one for the audio. Tie them together and then you will have a spare conductor in the stereo cable and jack. Not sure if it will give you ground loop problems but I don't think so.

    Senior Member

    May 26, 2009
    CDRIVE is correct, you need to have all the grounds connect together.