Build your own synth plugins
I’ve been building
SynthEdit since 1987.
It’s a modular environment for designing synthesizers and effects. You patch modules together on a canvas, draw a front panel, and export a VST3 or Audio Unit plugin. What you build is yours to sell or give away, with no royalties and no permission needed.
New in 1.6: SynthEdit now runs natively on macOS.
- WindowsNative, stable
- macOSNative, new in 1.6
- LinuxExperimental preview, free
The Linux build is an early preview. The editor itself needs a Wayland session, but the plugins you export from it carry both display-server paths in one binary, so they run in X11 hosts like Ardour and in Wayland ones. It’s all very new, and free while it’s in preview. Download it and see how far it gets you.
Nothing is hidden from you
There’s no layer underneath that you’re not allowed to see. Every oscillator, filter, envelope and bit of arithmetic is a module sitting on the canvas, and every connection is a wire you drew yourself.
Patch it together and listen
Drag modules onto the canvas and wire them up. The engine is running the whole time, so you hear each change as you make it. Hover any pin or wire and a small live scope shows you the signal passing through it.
There’s no wrong way to wire things up. Hook modules together in your own weird and wonderful ways and the programming turns into exploring, which is the part I still enjoy after all these years.
Build your first synth
Then draw the front panel
Lay out knobs, sliders, switches, graphs and your own bitmap artwork in the panel designer. What you draw is the window your users get when they open the plugin.
Export it and you have a 64-bit VST3 or Audio Unit that loads in any major DAW on Windows and macOS.
How exporting worksReal DSP, and a way out
The visual canvas is the whole program. Exporting a VST3 or Audio Unit takes one step. Going further than that takes real C++ experience, and the table shows which is which. Full technical specifications.
| Capability | Visual patching | Going deeper |
|---|---|---|
| Plugin formats | One-step export to 64-bit VST3 (Windows & macOS) and Audio Unit (macOS). No extra tooling, no build system to learn | Experienced C++ developers can take a third route: SE2JUCE exports the project as JUCE-compatible source, and JUCE reaches further formats. That route is real software development |
| Audio engine | 32-bit floating-point DSP at any sample rate | Every signal (audio, control voltages, envelopes) runs at full sample rate. No zipper noise |
| Polyphony | Up to 128 voices per instrument | Idle voices sleep automatically to spare the CPU |
| Modules | 300+ built in | Write your own DSP in C++ with the open SDK, or draw on hundreds of community modules |
| Interfaces | Drag-and-drop panel designer | Custom knobs, sliders, switches and bitmap art |
| Distribution | Royalty-free: sell what you build | Automate builds and releases with GitHub Actions |
Your work shouldn’t depend on me
- Everything you export is royalty-free
- Sell it, bundle it, give it away. I don’t take a cut and you don’t need my permission.
- The plugins you ship don’t phone home
- The built-in registration modules need no internet connection and no licence server. Your customers never talk to anybody’s server, mine included.
- One licence covers all current versions
- €170, and you buy it once. Major versions keep their own settings and don’t interfere with each other.
- SynthEdit itself activates online
- This is a change from earlier versions. The editor authorises over the internet, with offline activation available if you work disconnected.
- The door is unlocked, but it isn’t automatic
- If you outgrow SynthEdit, or simply don’t want to depend on it, SE2JUCE exports your whole project as JUCE-compatible C++ source. Walking through that door takes genuine software development experience. It does mean your work isn’t trapped in my file format.
What it doesn’t do yet
Things I’d rather you heard from me now than discovered on day three.
- MIDI
MIDI processing can be awkward. The VST3 format’s MIDI support is limited, and that constrains MIDI-effect-style plugins more than I’d like.
- Standalone
Exporting a standalone application isn’t supported yet. Today the built-in export targets are VST3 and Audio Unit.
- CLAP
CLAP support is available to preview on Linux. It isn’t ready on Windows or macOS yet.
- Linux
The Linux port is an experimental preview, with PipeWire audio. The editor needs a Wayland session. There’s no X11 build of it. Export works, but it’s brand new: the plugins carry both an X11 and a Wayland path in one binary and pick whichever the host offers, so test yours before you ship it. It’s free while it’s in preview.
Built with SynthEdit
Thousands of free and commercial plugins have been built with it, including instruments that ended up in professional studios.
Phasm
Three oscillators with FM modes, two filters, distortion and an XY pad.
Kx-Synth-X16
A free modular synth by KX77FREE (Xavier Kalensky), modelled on the EMS VCS3 and patched through a pin matrix.
Phenome
Prodyon’s free SoundFont player. It layers up to eight SF2 instruments, each on its own MIDI channel.
The demo is the whole program
Fully featured for 60 days, plugin export included. After that a licence (€170, paid once) keeps everything working, with no further restrictions.
Jeff McClintock, New Zealand