The ZVEX Fuzz Probe Vexter is a fuzz pedal with a twist: a theremin-like copper antenna built into an acrylic plate that lets you adjust one of the knobs, STAB, by moving your foot or hand close to the plate. ZVEX calls it the older brother of the Fuzz Factory, and describes it as a big favorite of experimental noise fans, with its varying oscillation pitch and strange fuzz guitar interactions1.
MusicRadar's reviewer Trevor Curwen summed the idea up as "A brilliantly bonkers marriage of a fuzzbox with a theremin," writing that ZVEX's Probe series "takes a pedal and adds theremin-like gesture control to it"2.
How the antenna works
The gesture control is the pedal's defining feature. The Fuzz Probe combines a Fuzz Factory with a copper antenna built into an acrylic plate. That antenna circuit, via the brightness of an LED and a photoresistive cell, controls the stability knob of the Fuzz Factory2. In practice, ZVEX puts it simply: the pedal "has a theremin-like antenna that lets you adjust one the knobs (STAB) by moving your foot or hand close to the copper plate"1.
The signal path from your movement to the sound runs in three steps:
- Your foot or hand moves close to the copper plate on the acrylic panel.
- The antenna circuit changes the brightness of an LED, which a photoresistive cell reads.
- The photoresistive cell drives the Fuzz Factory's stability knob, changing how the fuzz behaves2.
Because the antenna sits in the path between your movement and the STAB control, the pedal responds to proximity rather than contact, in the way a theremin responds to a hand near its antenna. The related Wah Probe in the Probe series uses an RF antenna for its gesture sensing, according to a MusicRadar buying guide4.
The antenna adjusts the STAB knob by proximity, so where you place the pedal on your board matters: the copper plate needs room for a foot or hand to hover over it without accidentally hitting a switch or knob.
The STAB knob and the Fuzz Factory circuit
The knob the antenna controls is STAB, the Fuzz Factory's stability control. The Fuzz Factory itself is a fuzz circuit that Aion FX describes as "essentially a classic Fuzz Face with a LPB-1 booster in front of it," with the twist that half of the components are replaced with knobs, allowing fine-grain control over the transistor bias5. The STAB knob is one of those controls, and on the Fuzz Probe it is the one the antenna drives, which is where the oscillation pitch and self-generating sounds the pedal is known for come from12.
ZVEX describes the sound in its own words as "varying oscillation pitch and strange fuzz guitar interactions, a big favorite of experimental noise fans"1.
Fuzz Probe and Fuzz Factory: the family
The Fuzz Probe and the Fuzz Factory are close relatives. ZVEX calls the Fuzz Probe "The older brother of the Fuzz Factory"1, and the Fuzz Factory line has since grown into a wide family of fuzzes. Premier Guitar, reviewing the Fat Fuzz Factory, noted that "with the exception of the Theremin-like Fuzz Probe, the Fuzz Factory hasn't really been updated," placing the Probe as the distinct branch of the family6.
| Pedal | What sets it apart |
|---|---|
| Fuzz Factory | The core circuit the Fuzz Probe is built on2 |
| Fuzz Probe | Adds the copper antenna and gesture control over STAB12 |
| Vexter Fuzz Factory | Fuzz Factory in the silk-screened Vexter series1 |
| Fat Fuzz Factory | A later branch of the Fuzz Factory family7 |
| Fuzz Factory 7 | A later branch of the Fuzz Factory family6 |
| Mastotron | A later branch of the Fuzz Factory family6 |
Vexter series versus hand painted
The Vexter in the name refers to ZVEX's lower priced series. According to ZVEX, "Vexter Series pedals are lower priced, featuring silk-screened art. The parts inside Vexters are identical to the hand painted pedals"1. The difference, in other words, is the enclosure artwork and the price, not what is on the board.
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Questions
How does the antenna on the Fuzz Probe work?
The Fuzz Probe has a copper antenna built into an acrylic plate on the pedal. The antenna drives a gesture-sensing circuit that, through the brightness of an LED and a photoresistive cell, controls the Fuzz Factory's stability knob. Moving your foot or hand close to the copper plate changes the stability setting, so you can steer the fuzz's behavior without touching a control.
Is the Fuzz Probe the same circuit as the Fuzz Factory?
The Fuzz Probe is built on the Fuzz Factory circuit, and ZVEX describes the Fuzz Probe as the older brother of the Fuzz Factory. The difference is the added copper antenna and gesture circuit: on the Fuzz Probe, the antenna and its LED and photoresistive cell take control of the stability knob, adding theremin-like gesture control on top of the fuzz.
What is the difference between the Vexter series and the hand painted ZVEX pedals?
Vexter Series pedals are lower priced and feature silk-screened art instead of hand painted enclosures. According to ZVEX, the parts inside the Vexters are identical to those in the hand painted pedals, so the difference is the artwork and the price, not the circuit or components.
How big is the ZVEX Fuzz Probe Vexter?
ZVEX lists the pedal dimensions as 7.50 by 4.70 by 2.40 inches, length by width by height. That is a larger footprint than a standard compact pedal, largely because of the acrylic plate that carries the copper antenna.
Sources (7)
- Fuzz Probe Vexter, ZVEX Effects
- Z.Vex Vexter Fuzz Probe review, MusicRadar, 2014-08-13
- Fuzz Factory Vertical by ZVEX, RockBoard PedalPedia, 2026
- 5 great wah pedals guitarists need to try, MusicRadar, 2021-06-24
- Flare Fuzz Machine / ZVEX Fuzz Factory, Aion FX, 2021-03-19
- Z.Vex Fat Fuzz Factory Pedal Review, Premier Guitar, 2013-06-18
- Fat Fuzz Factory Vexter, ZVEX Effects
