Re: How to wire a Ge Fuzz Face negative ground PNP

[R.G.]

Don't do this. It's a bad idea. It can cause intractible oscillation in some cases.

[marcoharder]

I see. So the only way for me to power the positive ground pedals is through a battery or a separate power supply, correct?

[petemoore]

  I typed something about using a MAX1044 converter to reverse PS polarity, *I don't see why it wouldn't work, but I haven't tried it on a FF.

[R.G.]

So the only way for me to power the positive ground pedals is through a battery or a separate power supply, correct?

I should be clear about this. You can often get away with it. But sometimes you can't, and I've spent a lot of time trying and failing to figure out why. So I advise people against it.

The options that definitely work are the ones you list - battery or separate positive-ground power supply.

The charge pump approach is a good one, as pete mentions. A charge pump inverter like the MAX1044 and others effectively make a separate positive ground power supply for the pedal out of the negative ground 9V. This works well if you implement it correctly.

There are a number of people who have successfully rewired a positive ground PNP pedal to negative ground, and those people will tell you it's fine. But they are the ones who have gotten away with it.

[marcoharder]

So the only way for me to power the positive ground pedals is through a battery or a separate power supply, correct?

I should be clear about this. You can often get away with it. But sometimes you can't, and I've spent a lot of time trying and failing to figure out why. So I advise people against it.

The options that definitely work are the ones you list - battery or separate positive-ground power supply.

The charge pump approach is a good one, as pete mentions. A charge pump inverter like the MAX1044 and others effectively make a separate positive ground power supply for the pedal out of the negative ground 9V. This works well if you implement it correctly.

There are a number of people who have successfully rewired a positive ground PNP pedal to negative ground, and those people will tell you it's fine. But they are the ones who have gotten away with it.

I see. I'd like to try the charge pump inverter method. Are there any schematics here in the site for that device?

[marcoharder]

I googled and ended up with RG's circuit! Thanks!

http://www.geofex.com/circuits/+9_to_-9.htm