OctaSine a free and open source frequency modulation synthesizer plugin

A free and open source frequency modulation-based synthesizer plugin. Runs on macOS, Windows and Linux in VST2-compatible hosts.

Features

Four operators

Four FM operators with parameters for volume, panning, modulation index, feedback, frequency modifiers (ratio, free and fine), envelope values (attack, decay, release) and toggling of white noise mode.

Flexible routing allows setting the operator modulation target (with some limitations) as well as the percentage of signal that is simply added to the final output, enabling additive synthesis.

Four LFOs with multiple waveforms, oneshot and loop modes and optional DAW BPM sync. They can target most operator parameters and most parameters of lower-index LFOs.

Audio samples

Frequently asked questions

How do I suggest improvements or report a bug?

If you want to suggest improvements or report a bug, please open an issue. To do this, you need to create a GitHub account. It is easier than it sounds - you only need an email address and a password.

If you’re reporting a bug, please use the “Bug report” template.

How do I export and import patches?

Please use the functionality provided by your DAW for exporting/importing .fxp/.fxb files.

Use the disk icon to save individual patches or the whole bank. Use the folder icon to select and load previously saved patches or patch banks. REAPER Use Export VST patch/bank file (.fxp/.fxb)

Why is the plugin called OctaSine?

The name OctaSine comes from the four stereo sine-wave operators. Frequency modulation is done twice per operator, enabling modulation panning.