Contact microphone, preamplifier, CV generator with an integrated envelope follower, gate output, and user-controllable attack and decay

Piezo is a contact microphone preamplifier and CV generator with an integrated envelope follower, gate output, and user-controllable attack and decay parameters. Its front panel features a dedicated tactile zone designed to be scratched, struck, or pressed, making the module itself a playable instrument.

Piezo is an original module inspired by a lineage of contact microphone interfaces: the Mikrophonie by Music Thing Modular (Tom Whitwell), the Ears by Mutable Instruments (Émilie Gillet), and the Radar by Behringer. All share the same foundational concept: turning physical vibrations into usable Eurorack signals.

• Integrated piezo microphone A piezoelectric sensor coupled directly to the panel’s tactile zone captures vibrations from scratching, tapping, pressing, or any physical interaction with the panel surface. The sensor also responds to vibrations transmitted through the case from external sources.
• External jack input A 3.5 mm jack accepts an external contact microphone or any mic-level source. When a cable is inserted, the external input takes over from the internal piezo.
• AUDIO output The amplified signal from the piezo or external input, at modular level and ready for further processing.
• ENV output A CV signal that follows the amplitude envelope of the input. The shape of this envelope is governed by the Attack and Delay knobs.
• GATE output A trigger or gate pulse fired when the input signal crosses the threshold set by the Sens knob.

https://www.davidhaillant.com/piezo/