Overtonium Free Additive Synth Receives September Updates
Dehli Musikk has updated Overtonium, a free open-source additive synthesizer featuring 32 harmonic sine channels. Originally launched on August 25, 2026, the instrument is available directly through public GitHub releases hosted on the developer website. This is a September update spotlight, not a new launch.
Additive synthesis
The sound generation engine in Overtonium is driven by 32 discrete harmonic sine channels, allowing producers to construct complex tones from fundamental sinusoidal partials. Rather than carving away frequencies using conventional subtractive filters, the instrument builds harmonic structures directly at the source.
The project is published as open-source audio software under the AGPLv3 license. Active maintenance has continued following its initial release, with updates including version 1.9.0 on September 23, 2026, and version 1.10.1 on September 30, 2026.
Formats and installation
Dehli Musikk provides downloads across desktop platforms without registration requirements or fees. When installing, note that while macOS downloads include a universal signed installer, the Windows package currently uses an unsigned installer, which may trigger system verification prompts during setup.
- Formats: VST3 and standalone (Windows, macOS, Linux), AU (macOS), LV2 (Linux)
- Synthesis engine: 32 harmonic sine channels
- Licensing: AGPLv3 open-source license
- Distribution: Public GitHub releases with no account sign-up
- Installer details: Universal signed installer on macOS; unsigned Windows installer
You can download the latest installers directly from the official Dehli Musikk website.
Overtonium is completely free under the AGPLv3 license with no expiration date or sign-up requirement.
FAQ
Is Dehli Musikk Overtonium really free?
The synthesizer is free and open-source under the AGPLv3 license with no trial limitations or required accounts.
What plugin formats does Overtonium support?
It provides VST3 and standalone versions for Windows, macOS, and Linux, Audio Units for macOS, and LV2 for Linux.