This distortion pedal schematic is for the Ibanez TubeScreamer TS-808. If you have electronics skill and the ability to read electronics schematics, I would suggest trying to mod one of these, fixing one, or even building a custom version of one from scratch. There are many possibilities for modding/customizing an Ibanez TubeScreamer TS-808 distortion pedal.
This schematic was taken from the great folks over at the General Guitar Gadgets homepage here: TubeScreamer Schematic.