A fOXX Tone Machine with several unique tricks up its sleeve, the FNTSTC pretty much rips.

In the course of a gear trade I offered a friend his choice of several circuits to develop into a Mr. Furious Audio pedal. He picked the fOXX, and I couldn’t be happier that he did; this is a great pedal with several interesting design elements. It can purr, it can tear your face off, and it has near-infinite sustain even at low levels.

Beyond the standard fuzz, tone, and volume controls the FNTSTC has:

  • A footswitchable octave with built-in low-passing for better tracking
  • A special tweak to avoid the momentary signal drop the originals and all clones I’m aware of have when switching the octave on
  • “MR” mode for a more modern fuzz sound with a less pronounced octave
  • “Pad” control for padding down the main fuzz level relative to the octave (so the octave can really jump out when you turn it on!)
  • More volume on tap than the original
  • Lower output impedance than the original (for driving long cable runs)
  • A slight shift of the tone control range toward more treble (all the classic sounds are still there, except for the extreme, nearly-unuseable full bass setting)


I – Input

O – Output

P – Pad. Turning the Pad down reduces the fuzz in the main mode relative to the octave mode. I chose this to retain the full-on original sound when the Pad is all the way up, so the sweep of the control doesn’t do much until about 10 o’clock and below

F – Fuzz

T – Tone

V – Volume

MR/FXX – MR / fOXX modes. fOXX is the classic sound; MR mode is a smoother, more modern fuzz with a less pronounced octave. In MR mode, sometimes the octave is more pronounced without the octave switch engaged. MR mode is more like two different shades of fuzz rather than a full-on octave.

(Unmarked footswitch, right side) – Bypass.

Up arrow footswitch, left side – Octave mode. Engaging the octave bypasses the Pad control