The Gecko Pedals O-Face Modulated Overdrive is an overdrive pedal with a twist: each of its three drive controls can be modulated on its own. Pedal of the Day reviewed it on its release in November 2023, describing it as combining "a tremolo, a tone-vibrato, a pulsed gain, and a killer-sounding original overdrive," and concluding that "the O-Face is like having four pedals in one"1. It sits in the wider field of overdrive pedals, but the modulation layer sets it apart from a conventional drive box.
What it does
At its core the O-Face is an original overdrive circuit. Gecko designed it, according to Pedal of the Day, "to produce the most authentic overdrive possible, sounding as much" like a tube amp being driven hard at high volume as possible1. On top of that drive circuit, the pedal "adds an industry first: independent optical knob modulation on each of the overdrive control knobs"1.
Modulating the Gain, Tone and Volume knobs
The modulation works like this:
- With the simple push of a button, any of the three overdrive controls, Gain, Tone and Volume, can be set to oscillate automatically1.
- Each modulation has its own independently configurable Speed, Depth, Waveform Shape and Phase1.
Because the three controls can move independently, the pedal covers ground that normally takes several boxes: modulating the Gain gives a pulsed gain effect, modulating the Tone gives a tone-vibrato, and modulating the Volume gives a tremolo, all stacked on the overdrive itself1. Players already familiar with tremolo pedals or vibrato pedals will recognize those effect types; here they come from the drive controls rather than a separate circuit.
How the optical modulation works
The technique borrows from a familiar piece of history. Pedal of the Day explains that the O-Face works "just as the legendary Uni-Vibe pedals used an LFO-driven incandescent bulb shining onto photo-sensitive resistors," with one change: "rather than using an incandescent bulb, the O-Face uses LEDs that will never burn out"1. An LFO, or low-frequency oscillator, drives the LEDs, and the changing light on the photo-sensitive resistors moves the control values.
Tap tempo, presets and MIDI
Unlike most overdrives, the O-Face carries the kind of feature set more often seen on MIDI pedals and multi-effects pedals. Pedal of the Day's verdict: "Tap Tempo, Presets, MIDI and more make this option-filled unit a must-have"1.
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Questions
Is the Gecko O-Face analog or digital?
Pedal of the Day describes the O-Face as a pure analog high-output drive circuit. The modulation is optical, using LFO-driven LEDs shining onto photo-sensitive resistors rather than digital processing, in a technique similar to the Uni-Vibe pedals but with LEDs in place of an incandescent bulb.
Does the O-Face have MIDI and presets?
Yes. Pedal of the Day's review notes tap tempo, presets and MIDI among the O-Face's features, calling it an option-filled unit. That makes it unusual among overdrive pedals, which typically offer only the drive controls themselves.
Does the O-Face have tap tempo?
Yes. The Pedal of the Day review lists tap tempo alongside presets and MIDI as part of the pedal's feature set.
How does the optical modulation in the O-Face work?
The O-Face uses LFO-driven LEDs shining onto photo-sensitive resistors, the same approach as the Uni-Vibe pedals except that the O-Face uses LEDs instead of an incandescent bulb, which Pedal of the Day notes will never burn out. The light falling on the resistors drives the modulation of the pedal's controls.
What can be modulated on the Gecko O-Face?
Any of the three overdrive controls, Gain, Tone and Volume, can be set to oscillate automatically with the push of a button. Each modulation has its own independently configurable Speed, Depth, Waveform Shape and Phase.
Sources (1)
- Gecko Pedals O-Face Modulated Overdrive, Pedal of the Day, 2023-11-22
