madBee::audio has released Optopus, a free optical-style compressor with tube saturation for Windows.
Optopus originally appeared in February, so this is an older freebie that we missed when it first arrived. It is still available, though, and I bumped into it this weekend, so I decided to share it because it offers quite a bit more control than the typical two-knob opto compressor.
The plugin models the program-dependent response associated with electro-optical hardware. That smooth response generally makes this style of compressor a good match for vocals, bass, guitars, and other sources that benefit from gradual leveling and don’t need aggressive transient control.
It is worth noting that Optopus is an original opto-style design, not an emulation of a specific unit such as the LA-2A (similar to our own free BPB Dirty LA)
You can switch between Compress and Limit modes, moving from gentle leveling toward firmer peak control. Optopus also provides a choice between feedback and feedforward operation, which changes how the detector responds and gives the compressor two noticeably different behaviors.
The frequency-shaped sidechain can place more emphasis on high-frequency content. This is useful when the low end is making the compressor work too hard, or when you want it to react more readily to brighter parts of the signal.
The optional tube-style saturation stage adds harmonic color, and you can use the Warmth control for adjusting its intensity and 4x oversampling to reduce aliasing. The Age control introduces component-drift-style variation, moving the circuit from a factory-new response to a more vintage character.
The video below provides a useful tour of the interface and demonstrates Optopus on several audio sources.
Optopus is available only as a 64-bit VST3 plugin for Windows. The public Patreon post provides the ZIP attachment without requiring a paid membership or email submission.
For more options across Windows and macOS, visit our regularly updated guide to the best free compressor plugins.
Download: Optopus (FREE)
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Last Updated on September 16, 2026 by Tomislav Zlatic.
