If I understand what a charge pump does correctly, it allows you to use a 9v power supply in a pedal that requires more than 9v to operate. PLEASE correct me if I'm wrong. So if that's the case, then why not just buy a 12/15/18v power supply if that's what the pedal needs? Are there benefits to a charge pump over the proper power supply and vice versa? Thanks for the help.

In one offs there's no benifit to the charge pumps imho.  They can't source a lot of current, and when the voltages drop down (weak battery) they can wig out.  but if you were going into production they have a place because a lot of the pwr supplies people have for their boards might not have the voltages you want.  If you designed a pedal for 18vdc it might not work as well being run on the standard 9 volt supplies.  The pumps let you have the pedals running on what you wanted.  You could go the two battery route also.   some production units do that.

The biggest reason to me is if you want to just plop the pedal on the floor without having to have it plugged into a supply.

there is a nice thing about using pumps to make negative voltages though.  Sometimes you don't want +18.  You might want +9/-9.  Pumps are nice for that with standard power supplies.

what I wish is that the "norm" was for 12VAC supplies.  that would open up a whole new world if all the supplies on the market had that.

Later, PaulC
Heritage amps/Tim & timmy pedals

I'm planning to put a charge pump in a FS&H-A1 build
just so I can power it on the same 9v daisy chain as my other pedals.

The benefit would be not having to add another power supply to the board.

I guess thats more like adapting a bi-polar powered effect to fit into a 9v world.

Yeah, the benefit for me is being able to daisy chain positive ground, bipolar or 18V pedals off the same PSU as "standard" 9V effects.  I've got an Ibanez FL-301 powered this way and it's a lot more convenient than using 2 batteries and then having to remember to unplug the pedal so they don't discharge, or having to use a second PSU.

Can I use a charge pump giving +9/-9 (like the one on GGG) inside a pos gnd pedal, taking the -9 out of it and connectig that pedal with others neg gnd pedals without problem?

Yes.

In fact, I would recommend that ALL positive ground pedals ought to be powered this way if the current they need is low enough. It ought to be part of the circuit board.

Thanks RG.

So, in this way i can power all my pos and neg ground pedals just with one power supply, avoiding buying (or building) an other one.

charge pump adds too much noise for me usually, rather use the correct supply if possible.

Quote from: analogmike on March 09, 2007, 02:15:44 PM
charge pump adds too much noise for me usually, rather use the correct supply if possible.

Thanks for the info.
An other problem i'm reading about is the voltage drop...

Maybe I'll try using a charge pump and see... by the way, if I'll use two or more pos ground pedals I'll build a bipolar power supply.