ZVex Wah Probe (often referred to as Wah Probe / Vexter Wah Probe / V2-style versions with the expanded controls) — the no-rocker, proximity-controlled wah that feels like a theremin crossed with a classic vocal filter.

Tired of rocker pots that wear out, stiff treadles that fight you, and wahs that only do “wah-wah-wah” the same old way? The ZVex Wah Probe throws the rulebook out and replaces the mechanical rocker with a theremin-style copper antenna/proximity sensor. Wave your foot (or hand) closer and the wah opens brighter; pull away and it closes. You get lightning-fast sweeps, chewy “pull-away” sounds, and expressive control impossible on a traditional treadle — with zero mechanical wear.

Why players fall in love with it

• Proximity RF sensing generates a small (roughly 1–2 inch) “bubble” of RF energy above the antenna plate. Your foot (or any conductive/wet object) disturbs the field, brightening an LED that optically controls the wah circuit. Super-fast action and smooth, continuous expression.
• Wah circuit is the same highly regarded filter used in ZVex’s Seek-Wah (minus the sequencer) — known for its distinctive, vocal, springy character that stands out from generic Cry Baby-style circuits.
• Built-in Super Hard-On™ boost sits in front of the wah. Crank the Volume/Drive knob and you can push the circuit into mild breakup or full “something’s gonna blow” overdrive while keeping the wah responsive and loud.
• Mix control lets you blend wet/dry signal — pure wah, subtle parallel filtering, or anything in between. Perfect for stacking with fuzz or distortion without losing note definition, and bass players love it too.
• Range control dials the upper brightness. Full clockwise gives the ultra-bright, almost synth-like sweep of the original Probe; turn it back for more traditional, vocal wah ranges.
• Bottom-mounted RF trimmer lets you fine-tune sensitivity and the resting (foot-away) position of the wah so it parks exactly where you want it.

Key specifications

• Effect type: Analog wah / filter with proximity control
• Control method: Theremin-style RF proximity sensor (copper antenna plate) — no rocker pot
• Circuit basis: Seek-Wah filter + Super Hard-On boost stage
• Controls:
  – Range (upper frequency/brightness limit)
  – Volume / Drive (Super Hard-On boost level)
  – Mix (wet/dry blend)
  – Internal RF sensitivity trimmer (bottom of enclosure)
• Switching: True bypass
• Power: 9V battery or standard regulated 9V DC (Boss-style center-negative barrel)
• Construction: Available in Vexter (silk-screened, more affordable) and hand-painted versions; same internal circuitry
• Form factor: Floor pedal with antenna plate on top

This is pure Zachary Vex weirdness in the best possible way: innovative, musical, and built to inspire new playing approaches rather than just recreate the past. Whether you want classic cocked-wah tones, rapid-fire funk, dramatic sweeps, or overdriven filter screams, the Wah Probe delivers expression that a conventional rocker simply can’t match.

Original box is included. Condition? The volume knob is a bit "noisy" when turned. Set the volume before you start playing. Otherwise the pedal works perfectly and sounds fantastic!