Last year, I received an old Kasha "Guitar OD" pedal in for repair. It was gooped and zero hints of a schematic available on the web and no response from Kasha communiques. So I meticulously removed the goop and traced it. I was quite surprised to discover this OD uses zero clipping diodes. The only active components in it are two JFETs. Enjoy! (Posted again because the images on the original posting will NOT display.)
If you decide to build or breadboard this out, the Vgs(off) of the JFETs selected are vital and you may have try a few different Vgs(Off) values to the great OD this thing can deliver.
http://www.endprod.com/schematics/WOS_P ... Layout.jpg
http://www.endprod.com/schematics/WOS_P ... rected.png