ZVEX Mastotron Review — The Fuzz With a Choke Chain

Most fuzz pedals give you one fuzz and a volume knob to apologize for it. Zachary Vex looked at that and built the Mastotron with a Pulse Width control — PW — that reshapes and starves the circuit, so you can drag it from a smooth, full wall of fuzz all the way down to gated, sputtering, coughing, dying-battery splatter. One pedal, and it covers the whole spectrum from “beautiful” to “broken on purpose.”

What It Is

A silicon fuzz from ZVEX, the shop that treats pedals like art projects. Volume, Tone, and Fuzz do the expected work — but the character lives in the parts most fuzzes don’t have: the PW knob that squares off and gates the signal, a Relax/Push control that changes how hard the circuit bites into the note, and a Subs toggle that drops a sub-octave rumble underneath everything. It cleans up off the guitar volume better than a fuzz this unstable has any right to.

How It Sounds

Enormous at one end, gloriously falling-apart at the other. Open the pulse width up and it’s a rich, saturated fuzz that fills a room. Pinch it down and every note gates and stutters like the pedal is gasping — that broken, synth-y, velcro-ripping texture noise players and studio weirdos hunt for. Flip the Subs toggle and the low end goes subterranean. It’s the rare fuzz that’s genuinely two or three different pedals depending on where you set it.

Bottom Line

I love this pedal, and I’m still giving it a 27 out of 36 — Master — because loving something isn’t the same as it rewriting the category. The Mastotron is excellent, deep, and more versatile than most fuzzes dream of being. It’s not a 33 because it’s a wild, specialized tool, not a universal one — the gated splatter that makes it special is also the thing that keeps it off some boards. But if your idea of fun includes making a guitar sound like it’s malfunctioning beautifully, few pedals do it better. Real strengths, easy recommend, and yeah — I love it.

Protect Ya Tone. Then choke it out and see what happens.

More info: the Mastotron at ZVEX — straight from the maker, $179.