Audio-to-CV Pitch, Envelope, and Trigger Converter

The RS-35 tracks incoming external audio signals and extracts pitch control voltages, dynamic envelopes, and gate triggers to control modular patches in real time.

This utility converts line, instrument, or acoustic audio sources into standardized Eurorack control signals. Instead of relying on traditional keyboards or sequencers, you can play your system using voice, guitars, hardware drum machines, or external synths.

The internal architecture splits an incoming signal across three simultaneous analysis paths. The pitch section tracks fundamental frequencies and converts them into precise tracking CV, using a switchable frequency range selector to maintain accuracy across bass or lead registers. A slew control adds variable glide to smooth out rapid pitch jumps, while a held CV output locks onto the last detected pitch until a new note registers. Simultaneously, the envelope follower converts dynamic changes into continuous voltage, while the trigger generator fires a gate pulse whenever the input breaches a adjustable threshold.

In practice, the module demands clean, monophonic source material for accurate pitch tracking. Complex polyphonic audio or heavily distorted signals will produce unpredictable pitch jumps, though this can be exploited intentionally for generative CV patterns.