Hey,

I recently built an AMZ filtered power supply that has an 18V output:

http://www.muzique.com/power.htm

I would like to use this output to power a Neutron Mutron III clone that I will be building soon.  The problem is that in the two layouts that I have for the pcb I purchased from GGG, the input voltages require 3 leads generated from two 9V power inputs: +9V, GROUND, and -9V, as depicted in the following link:

http://www.geofex.com/PCB_layouts/Layouts/neutronpub.pdf

There is another layout that shows a single battery +9V, GROUND connection with a charge pump:

http://www.geofex.com/FX_images/neutron-tbp.pdf

I don't want to use the charge pump on the single battery, as I have read this can introduce noise.  Does anyone have any ideas on how I can set this up just using my 18V source?  Any suggestions are greatly appreciated, as always.  Thanks in advance for your help!

Patrick

You can just split the +18V into +/-9V.  You could do this by connecting two 10megohm resistors between +18V and ground.  The middle node (which is at +9V) will function as your circuits ground.  This will let 0V (the power supplies ground) be -9V and the 18V act as +9V.

Quote from: phoganuci on June 12, 2010, 11:04:56 PM
I recently built an AMZ filtered power supply that has an 18V output:
...
I would like to use this output to power a Neutron Mutron III clone that I will be building soon.  The problem is that in the two layouts that I have for the pcb I purchased from GGG, the input voltages require 3 leads generated from two 9V power inputs: +9V, GROUND, and -9V, as depicted in the following link:

There is another layout that shows a single battery +9V, GROUND connection with a charge pump:
...
I don't want to use the charge pump on the single battery, as I have read this can introduce noise.  Does anyone have any ideas on how I can set this up just using my 18V source?  Any suggestions are greatly appreciated, as always.  Thanks in advance for your help!

If I read the image on that web page correctly, it already includes a charge pump to make -9V from the +9V. You already have the solution in hand.

As for "I have read this can introduce noise." - It might be worth your time to try it out with the power supply you already have and find out if "CAN introduce" comes true.

Quote from: jbord39 on June 12, 2010, 11:11:13 PM
You can just split the +18V into +/-9V.  You could do this by connecting two 10megohm resistors between +18V and ground.  The middle node (which is at +9V) will function as your circuits ground.  This will let 0V (the power supplies ground) be -9V and the 18V act as +9V.

Maybe. You'll want to read "Designing bias networks to provide Vbias in effects" here: http://geofex.com/circuits/Biasnet.htm