OctaSine

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

Latest release

OctaSine v0.8.0

2022-08-28 - Release notes

After downloading the archive, unzip it and move OctaSine 0.8.vst to your VST2 plugin directory. Typically, it is /Library/Audio/Plug-Ins/VST/.

You might need to allow MacOS to open applications from any developer. To do this, open a terminal window, enter sudo spctl --master-disable, press enter, enter your password and press enter again. More info here.

Distributed under the AGPLv3 license.

After downloading the archive, unzip it and move OctaSine 0.8.dll to your VST2 plugin directory. The standard locations are:

C:\Program Files\VSTPlugins or
C:\Program Files\Steinberg\VSTPlugins or
C:\Program Files\Common Files\VST2 or
C:\Program Files\Common Files\Steinberg\VST2

Distributed under the AGPLv3 license.

After downloading the archive, unzip it and move OctaSine 0.8.so to your VST2 plugin directory.

There is also the option of building OctaSine from source.

Distributed under the AGPLv3 license.

OctaSine screeshot

Features

Four operators

Four FM operators with parameters for wave form (sine or noise), volume, panning, feedback and frequency (ratio, free and fine), with visualizations of stereo wave forms after modulation.

Flexible routing

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

Four LFOs

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.

ADSR envelopes

Each operator is connected to an attack-decay-sustain-release volume envelope with logarithmic slopes. Envelope groups make synchronizing changes a breeze.

Modulation panning

A unique feature of OctaSine is that modulation can be panned, enabling positioning FM within the stereo image. Additionally, true stereo panning is implemented, not just balance.

Cross-platform

Runs on macOS, Windows 10 and Linux (X11) in VST2-compatible DAWs on 64-bit computers. Synthesis is SIMD-accelerated on x86_64.

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 do fine adjustments to parameters?

Hold shift while dragging knobs to make fine adjustments.

How do I reset parameters to the default value?

Double-click knobs to reset their value to the default.

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.