Joakim Frostegård releases OctaSine, a free (open-source) 4-operator FM synthesizer in VST plugin format for digital audio workstations on Windows, macOS, and Linux.
OctaSine is a capable four-operator FM synthesizer with independent volume, panning, feedback, and ADSR controls for each operator. It takes inspiration from popular virtual FM synths like the FM8 from Native Instruments.See also: Free Synthesizer VST Plugins
The current build is v0.5.1, and the project is still a work in progress. That said, OctaSine is already a useful instrument, and you can definitely give it a try if you’re looking for a virtual FM synth. However, keep in mind that future updates might not be backward compatible.
Back to OctaSine, the plugin sports a great-looking user interface with an intuitive control layout. FM synths are notorious for their steep learning curve, but OctaSine’s simple monochrome GUI will make the learning process at least a bit less difficult.
Each operator has a dedicated section with the most important controls laid out horizontally. The bottom half of the GUI is where you’ll find the four LFO modules, each capable of operating in sync with the host DAW.
One interesting trick here is OctaSine’s “white noise mode,” which is available for each operator. This mode is a godsend for designing percussive sounds like drums, cymbals, or hats.
As of right now, the software comes with 128 preset slots, but I couldn’t find a way to store the current patch as a preset. This info might be available somewhere in the manual, so you’re welcome to post a comment below if you discover how patch management works.
As already mentioned, OctaSine is fully cross-platform. It is available for all VST plugin hosts on Windows, macOS, and Linux.
Being an open-source project, I’m looking forward to the further development of this promising FM virtual instrument. Thanks to the developer Joakim Frostegård for making it free.
Download: OctaSine (3.02 MB download size, ZIP archive, 64-bit VST2 plugin format for Windows, macOS, Linux)