gregory

Monophonic software synthesizer

Summary

Gregory is a one-oscillator subtractive monosynth written in Rust. It has a band-limited sawtooth and square oscillator with optional unison mode, a four-pole Moog-style low-pass filter, dual ADSR envelopes for amplitude and filter modulation, plus portamento for smooth pitch gliding between notes. It accepts input from any connected MIDI keyboard and runs on macOS, Linux and Windows via native audio APIs.

Usage

Run in terminal:

$ gregory
Output device: MiniFuse 4
Sample rate: 48000  Channels: 6  Format: F32
Available MIDI ports:
  [0] KeyStep Pro
  [1] MiniFuse 4
MIDI input: KeyStep Pro
MIDI connected

Then tweak the knobs and faders or just click dice to create a random patch. Save patches with Cmd+S and load with Cmd+O. Create a new default patch with Cmd+N. By default patches saved in ~/.config/gregory/patches as TOML files.

Installation

Prebuilt binaries for macOS, Linux and Windows are available on the releases page.

To build and install from source with Cargo:

cargo install --git https://github.com/eiri/gregory

Motivation

This is an educational project with two goals.

First, to explore writing audio software in Rust with a look at options for lock-free concurrency between audio and MIDI threads.

Second, to learn software sound synthesis practically by writing from the ground up oscillators, filters and envelopes.

The implementation is intentionally kept simple.

Name

Gregory is named after Gregorian chant, since it's monophonic, one voice at a time.

License

Licensed under either of MIT or Apache 2.0 at your option.