This ColorSound stompbox may have been sold during the same time period under the name of SolaSound™ ToneBender™ and possibly ™ Vox ToneBender™. There seems to be no difference between the circuits inside the different brand names.

For a simple, great sounding project, we recommend the “NPN Silicon Transistor Version”.

If you have a common power supply to power your pedals, the negative ground versions (NPN transistor versions) will work with other pedals on a common power supply. If you build one of the “PNP Germanium Transistor Versions”, you can only share the same power supply with other POSITIVE GROUND effects pedals unless you use the Charge pump circuit with is as shown below.

Description from General Guitar Gadgets.