convert circuit from single to dual supply

Discussion in 'General Electronics Chat' started by yardcat, Apr 24, 2009.

  1. yardcat

    Thread Starter New Member

    Nov 27, 2008
    I am very curious as to the how of converting a battery powered elec guitar effect to using a dual supply. The circuit, which I have attached, runs on a 9 volt battery. The supply is divided, +9v, +4.5v, and gnd. If I am using +9v,0v, and -9v, what do I need to do to adapt the circuit?

    There is a lot of information on converting to a single supply and none that I could find in converting to a dual supply. Any help would be appreciated. I am sure you can tell, my grasp of electrical engineering is weak. Thanks, yardcat
  2. mik3

    Senior Member

    Feb 4, 2008
    Use only the +9V and ground wires, power the 9V lines directly (if the power supply is regulated) and use a voltage regulator (like LM317) to regulate the 9V to 4.5V.
  3. Wendy


    Mar 24, 2008
  4. SgtWookie


    Jul 17, 2007
    The "quick" conversion would be to wire two 9v batteries in series (one +/red lead to one -/black lead).

    Remove the portion of the circuit that's dividing the single 9v supply to 4.5v.

    Connect the common connection between the two batteries to what was the +4.5v supply, which will now be 0v/ground.

    Connect the + (red) lead of the two batteries to what was the +9v supply.

    Connect the - (black) lead of the two batteries to what was the ground, which will now be -9v.

    This doesn't address the shield connections; they would now be connected to -9v instead of the new 0v/ground. You're probably using 1/4" mono phono plugs/jacks. Those would need to be rewired.

    C9 should be replaced with a non-polarized capacitor.