Based on the Foxx Tone Machine this Fuzz goes from overdrive to crazy fuzz, yet without the octave chords do not loose their definition.
With the octave engaged it produces som singing lead sounds, the clipping with octave is a little more subtle than from the blue octafuzz.
It doesn't work so well into drives, sound gets to muddy, but it does accept an Ampeg Scrambler Fuzz in front, that way it just takes a foot tap to go from subtle chord friendly fuzz to insanity.
I recommend trying both 9 and 12V, since there is a difference to be heard, personally I prefer 12V.