replacing 2 batteries with 9 volt adapter

[rm -rp ./Matt*]

Hello everyone,
this is my first post here, just finished my first build (Tweak-O from Small Bear Elec) and I'm hungry for more, need to learn a bit more about circuitry though.

I understand it's not complex to replace or add a 9v jack into one battery pedal, but what about these pedals that require 2 batteries? Should you just install 2 9volt jacks or do you install an additional pcb that converts the 9v to something higher? I've seen something like this on a diy spring reverb schematic, but forgot what it's called. :s

Matt

[Dr Ron]

In general, no. Two batteries are used for plus and minus nine volts. Only a few power supplies can have the + grounded.

GGG has a +/- 9 volt source.
http://www.generalguitargadgets.com/index.php?option=com_content&task=view&id=137&Itemid=26

[rm -rp ./Matt*]

ahh ok, thanks, so a as nine volt power adapter jack has a 2 9v sources (tip and ring?) as opposed to a single battery, which only has one, only one jack is needed?

Sorry if my wording isn't right.

[Dr Ron]

You'd need to use two power supplies - on for +9V and another for -9V.

Although it is possible to use two connectors, it's best to use a single three-wire connector.
That way you won't plug -9V into an effect by mistake.

[rm -rp ./Matt*]

thanks for all your help, one other thing though, I've read a charge pump can can output power from one battery into +9v and -9v, can the battery in this situation be replace with a 9v adapter? Probably not as I am yet to find a schematic for this, thanks again.

Matt

[Dr Ron]

here's one
http://www.generalguitargadgets.com/index.php?option=com_content&task=view&id=138&Itemid=26