The Octavix gives you that 1960's fuzzed out octave up that really defined a sound of a generation. With a voltage switch that changes the voltage supply from 9 to 24 volts to give two distinct sounds. The 9 volt setting gives a nice loose sounding fuzz, almost like the tone a a voltage sag. The 24 volt setting gives a nice tight and higher defined octave up. A highly versatile octave fuzz.