From what I understand the Original Pedal power has Dip switches on the underside. If they are in the ON position it is for the 9 volt supply, if the switch is in the OFF position it is for 12 volt supply. (Which is the complete opposite of the Pedal Power 2 version).
Check out this Voodoo Lab discussion link re: Original Pedal Power:
http://www.voodoolab.com/forum/viewt...7&t=521&p=1328