Black Diamond Distortion, filter.tank, Tentacles: Free Plugins of the Week
Is Black Diamond Distortion really “the one distortion plug-in to rule them all”, as the developer claims? Find out in this week’s round-up of free plugins!
Free Plugins of the Week
Aspen Instruments Black Diamond Distortion: Simulate any other Distortion!

It’s always great to see new developers come up with free plugins with an interesting concept, and Black Diamond Distortion by Aspen Instruments is no exception! It features a flexible distortion engine designed to emulate pretty much any other distortion, from subtle saturation to aggressive waveshaping. The plugin comes with a library of presets that includes a bunch of hardware-inspired designs, but you can also design your own effects from scratch.
The curve editor offers four editing modes. Harmonic mode gives you control over which harmonics are excited by the algorithm, making it easy to dial in great-sounding effects. Spline mode lets you shape the curce using spline anchors, allowing for extreme changes with minimal editing. Brush mode lets you draw the curve pixel by pixel, which is bound to result in unusual shapes and thus sounds. And lastly, Equation mode is based on mathematical equations. With this much flexibility, Black Diamond Distortion lets you design an extremely wide spectrum of custom distortion effects.
But that’s not all. There’s also a companion plugin called Black Diamond Probe that you can use to reverse-engineer your favorite hardware or software distortion effects. The Probe scans the unit and extracts the nonlinear transfer function that defines its behavior. This can then be imported into Black Diamond Distortion as a new preset. Truly fascinating stuff – especially for a free plugin!
Black Diamond Distortion is available for macOS and Windows in VST3 and AU formats.
Sender Spike filter.tank: Is this as Close as you can Get to the Sherman Filterbank with Software?

Sender Spike has released filter.tank, a free filter plugin inspired by the iconic Sherman Filterbank. Part of the appeal of the original hardware is that it’s notoriously hard to tame, and many would argue that it’s impossible to emulate in software. While Sender Spike doesn’t claim that filter.tank is an exact emulation, he’s confident that it’s pretty close.
Like the original, filter.tank offers dual resonant filters that are continuously variable from low-pass to band-pass to high-pass and can operate in parallel or serial configurations. The plugin also offers extensive envelope and LFO modulation, filter FM and AM, and an input drive stage. It’s all there!
filter.tank is available as a VST plugin for Windows.
Sunbunny Tentacles: Quadruple Stereo Vibrato that’ll Make your Head Spin

Sunbunny Tentacles is a delightfully spaced-out quadruple vibrato effect that’ll add dimensional width, shimmer, and, if you like, slightly psychedelic modulations to any signal. Unlike most other modulation effects, Tentacles splits the signal into four parallel processing chains, each consisting of vibrato, a band-pass filter, saturation, and stereo position controls.
The X/Y pad lets you control these four “tentacles” in real time, with the X axis representing the stereo position and the Y axis controlling the frequency band. For example, you could have a couple of tentacles modulating the low frequencies in the center of the stereo image, while the other two add spatial modulation and width to the high frequencies. A very unique and quirky take on a classic modulation effect!
Tentacles is a VST3 plugin for macOS, Windows, and Linux.
Check out our archive for more free plugins like Black Diamond Distortion, filter.tank, and Tentacles!
