OpenSynth1 is a tribute-focused synthesizer plugin and standalone app with its own DSP shaping, UI, preset handling, and ADSR behaviour. It is inspired by the classic Synth1 workflow and the Nord Lead 2 feel, but it is not a byte-for-byte clone of Daichi Laboratory's original Synth1.

This repository is a tribute project for the Synth1 aesthetic and sound architecture, with a custom ADSR implementation that intentionally differs from the original Synth1 mapping when loading existing bank presets. The ADSR curve and timing are tweaked for a more pronounced, personal attack / release response.

Preset files open, but they will not sound identical to the original Synth1 because the envelope timing, ADSR behavior, and voice shaping here are intentionally differentiated for a tribute-oriented implementation. But they sounds kinda similiar...

The project codebase and DSP/UI scaffolding were written with AI-assisted development tooling, and this repository is framed as an independent tribute project rather than an exact clone of Daichi Laboratory's original Synth1.

• Oscillator 1:
  • Waveforms: Sine, Saw, Pulse (with variable pulse width and PW modulation), and Triangle.
  • Sub-Oscillator: 1 or 2 octaves below Osc 1 for massive sub-bass weight.
  • Frequency Modulation (FM): Audio-rate modulation of Osc 1 frequency by Osc 2.
• Oscillator 2:
  • Waveforms: Saw, Pulse, Triangle, and White Noise.
  • Semi-tone Pitch (-24 to +24) and Fine-tune (-64 to +63).
  • Hard Sync: Phase syncs Osc 2 to Osc 1 for piercing lead sounds.
  • Ring Modulation: True analog-style ring modulation between Osc 1 and Osc 2.
  • Keyboard tracking on/off.
• Oscillator Modulation Envelope:
  • Dedicated Pitch/Mod envelope with variable Attack/Decay and depth routing to Osc 2 Pitch or FM.

• Filter Types:
  • 24 dB/oct Low Pass (Warm ladder-style response)
  • 12 dB/oct Low Pass
  • 12 dB/oct Band Pass
  • 12 dB/oct High Pass
• Filter controls: Cutoff, Resonance, Saturation (drive), and Keyboard tracking.
• Dedicated Filter ADSR Envelope with bipolar envelope amount (-64 to +63).

• Dual LFOs (LFO 1 & LFO 2):
  • Waveforms: Triangle, Saw Down, Square, Random (Sample & Hold).
  • Tempo sync to host / internal BPM with musical beat divisions (1/1, 1/2, 1/4, 1/8, 1/16, triplets, dotted), or free running frequency in Hz.
  • Flexible routing to Pitch, Filter Cutoff, Osc 2 Pitch, Pan, and Amp.
• MIDI Modulation Routing:
  • Real-time routing from Mod Wheel (CC 1), Aftertouch (Channel Pressure), Pitch Bend, Breath, and Foot Pedal to any parameter target.
• Amplifier Section:
  • Full Amp ADSR Envelope.
  • Gain and Velocity Sensitivity control.

• Up to 32-voice polyphony.
• Play modes: Poly, Mono, and Legato (with legato glide).
• Unison: Multi-voice stacking with adjustable detune and stereo spread.
• Portamento / Glide: Time control and Auto-glide mode.
• Arpeggiator:
  • Modes: Up, Down, Up/Down, Random.
  • Beat sync (1/4 to 1/32, dotted & triplets), Octave range (1 to 4 octaves), and Gate length.

• Stereo Delay: Host BPM sync, feedback, wet/dry mix.
• Chorus / Flanger: Depth, rate, and feedback for lush stereo widening.
• Distortion / Overdrive: Analog saturation for added bite and harmonics.
• Tone / EQ: Two-band shelving tone control.

• Full .sy1 format compatibility: Can import and export original Synth1 bank .sy1 preset files!
• Built-in preset browser and program selector.
• Options dialog for customizing color schemes and global settings.

Pre-built binaries for Linux x86_64 are available in the GitHub Releases section:

(Also available as .zip archives)

The pre-built binaries are compiled on Ubuntu 22.04 and require glibc ≥ 2.35.

This covers:

• Ubuntu 22.04 LTS (Jammy) and later
• Debian 12 (Bookworm) and later
• Linux Mint 21 and later
• Fedora 36 and later
• Most distros released after 2022

Not sure which glibc version you have? Run this in your terminal:

ldd --version | head -n 1

Example output:

ldd (GNU libc) 2.36

If the number shown is ≥ 2.35 → you're good to go ✅

If it's < 2.35 and not working → 🫏 BRUTTO SOMARO you'll need to build from source (see below) or upgrade your distro — instead of harassing the creator with kids vibe coding jokes.

1. Download OpenSynth1-Linux-x86_64-vst3.tar.gz from the Releases page.
2. Extract the archive:

   tar -xzvf OpenSynth1-Linux-x86_64-vst3.tar.gz

3. Copy OpenSynth1.vst3 to your user VST3 directory:

   mkdir -p ~/.vst3
   cp -r OpenSynth1.vst3 ~/.vst3/

4. Rescan plugins in your DAW.

1. Download OpenSynth1-Linux-x86_64-standalone.tar.gz.
2. Extract and run:

   tar -xzvf OpenSynth1-Linux-x86_64-standalone.tar.gz
   ./OpenSynth1

sudo apt-get update
sudo apt-get install -y build-essential libasound2-dev libfreetype6-dev \
    libx11-dev libxinerama-dev libxext-dev libfontconfig1-dev libcurl4-openssl-dev \
    libgl1-mesa-dev libgtk-3-dev pkg-config

git clone https://github.com/letsdig/OpenSynth1.git
cd OpenSynth1

# Clone the JUCE framework if not already installed:
git clone --depth 1 https://github.com/juce-framework/JUCE.git ../JUCE

cd Builds/LinuxMakefile
make CONFIG=Release -j$(nproc)

The compiled binaries will be located in Builds/LinuxMakefile/build/:

• OpenSynth1.vst3 (VST3 bundle, copy to ~/.vst3/)
• OpenSynth1 (Standalone executable)

This repository currently ships the Linux makefile exporter in the JUCE project file, so the committed build path is Linux-first. If you want a local macOS build, the simplest route is to use JUCE Projucer and export an Xcode project locally:

xcode-select --install
brew install git cmake

git clone https://github.com/letsdig/OpenSynth1.git
cd OpenSynth1
git clone --depth 1 https://github.com/juce-framework/JUCE.git ../JUCE

# open JUCE Projucer and load OpenSynth1.jucer
# then add/export an Xcode target and build the Release scheme

On macOS you can create the Xcode project from the Projucer UI, then open the generated .xcodeproj and press Build in Release mode. The resulting plugin/standalone bundle can then be copied to the usual mac VST3 or AU folders.

Since OpenSynth1 is modeled on Ichiro Toda's classic Synth1 workflow, the original Synth1 documentation serves as the complete parameter and sound design reference:

• Synth1 Complete Illustrated User Manual (PDF) (Compiled by Zoran Nikolic)
• Synth1 Interactive Web Guide (Robert Heaton)
• For full architectural details, see documentation.md.

• Inspired by Ichiro Toda (Daichi Laboratory), creator of the legendary Synth1 (2002).
• Architecture modeled on the hardware Clavia Nord Lead 2.
• Built with the JUCE Framework.

MIT License. See LICENSE for details.