RCJacH has released RCSiner, a free distortion plugin for macOS and Windows, now available as a standalone plugin.
RCSiner is a waveshaping and phase-distortion effect built around sine-based shaping formulas. While the project has been floating around in various forms before (I first saw it mentioned in 2025, but haven’t featured it on BPB then), the important update here is that RCSiner is now packaged as a proper plugin, with version 1.01 available as a free download from GitHub.
I have to admit that RCSiner looks a little intimidating at first. The interface has a scientific vibe (sort of like how MeldaProduction plugins would look without any added polish), and it’s definitely not what you’d expect from a modern distortion plugin (which usually try to mimic hardware like tube amps or guitar pedals).
Instead, RCSiner simply displays its parameters, a math formula, and a large waveform.
But I dig this one a lot. Instead of relying on a flashy GUI and easy workflow at the cost of a narrow sound palette, RCSiner gives you tons of control over how the signal is shaped. It’s capable of both very gentle harmonic enhancement and extreme distortion, but it offers much more nuance than most other distortions I’ve tried.
The selectable shaping algorithms are based on sine functions. Each algorithm includes three main parameters (Sync, Pull, and Deform), which let you control the rate, symmetry, and thickness of the shaping curve.
Do note that even small adjustments can dramatically change the character of the distortion, which is why RCSiner works so well both as a subtle saturator and as a crazy sound mangler.
You should also pay close attention to the Stages control. Increasing the number of stages effectively chains multiple instances of the same shaping process, so you can basically push the sound much further without having to stack plugins manually.
There’s also built-in oversampling to reduce aliasing, with separate settings for real-time playback and offline rendering.
RCSiner also includes gain-staging tools like input and output gain, optional clipping at both stages, and a dry/wet mix control for parallel processing.
A warning is warranted here: the plugin can produce extremely loud signals if driven hard, so using the output clipper or carefully managing levels is essential.
I highly recommend watching the developer’s walkthrough video.
It’s one of the best and funniest plugin demos I’ve seen in a while, not just because it’s fun, but because it clearly explains how the plugin works.
The video covers real-world use cases like bass, guitars, and fuzz-style distortion, and it does a great job of demonstrating just how wide the sonic range really is.
RCSiner is free, open-source, and provided as-is, with no guarantees of future updates. It’s available in VST3, CLAP, and Audio Unit formats for macOS and Windows.
Download: RCSiner (FREE, click here to access the downloads)
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Last Updated on January 31, 2026 by Tomislav Zlatic.
