There is several versions of this one but the 4-knob version seem to be the most common version.
Initially, it was a custom fuzz for doom band Conan but it was later slightly modified and morphed into Dunwich/Magic Pedals lineup of pedals. Traced by evilarsen and fuzzhead who both dig the sounds coming out of this doom circuit...
...and here is what evilrsens build looks like.
