Developer Sender Spike has released filter.tank, a free, modulated dual-filter plugin inspired by the Sherman Filterbank 2, the iconic Belgian analog filter unit from Sherman Audio. It is available as a 64-bit VST plugin for Windows.
The Sherman Filterbank is known for its extreme resonance and nonlinear saturation. Many people claim the sound can’t be replicated in digital form.
Sender Spike disagrees, saying that filter.tank came pretty close and made him appreciate the original hardware design even more. The developer doesn’t call it a direct emulation, but says the ballpark is there with some added features not available in the hardware.
I’ve never used the original Sherman Filterbank, but I tested the filter.tank, and I really love the sound.
I love filters in general and have tested dozens upon dozens of filter plugins, so I’m hard to impress. This one is pretty cool.
The weird thing is that a filter is such a simple concept, and it might seem wild to think that you need more than one plugin. In essence, it’s just a cutoff control and resonance, and yet somehow I have more than 20 filter plugins in my DAW.
The reason is that every good filter has its own character, and filter.tank is definitely one with its own sound. If you’re like me and enjoy trying different filters to see what works best, give this one a try.
By the way, I love filters so much that the first free plugin we ever released on BPB was the BPB Dirty Filter, which has become quite popular. If you enjoy filters, try that one too.
filter.tank is more than a basic filter, though.
It features a dual filter structure with independent frequency and resonance controls, and the two filters can be continuously morphed between parallel and serial routing. Each filter can also morph continuously from lowpass through bandpass to highpass.
But the resonance is the really fun part. It gets really wild at higher settings. Try this on some percussion loops with very high resonance for very cool dancing filter effects.
You also get input drive (up to +30 dB), a Harmonics control that links Filter 2’s frequency to Filter 1 in musically relevant intervals, and a noise section with white noise, clock noise, and feedback.
For modulation, there’s a tempo-syncable LFO with six waveforms, a filter envelope that can switch between ADSR and envelope follower mode, FM from the input signal, and AM (ring modulation). The gate can be triggered by audio input, MIDI, or DAW automation. It’s a fun plugin with a lot of depth.
This is the second standalone effect to come out of Sender Spike’s work on SN Zero, the FM synth we featured back in January. The first was qb, a multimode distortion plugin we covered in February.
Both were originally planned as part of SN Zero’s output stage but ended up as separate plugins, which I think was a great decision. This way, you can use them with any source, including SN Zero itself.
Oh, I almost forgot to mention the interface. It is entirely text-based! All values are displayed as numbers (hertz, milliseconds, percentages) instead of knobs and sliders.
I personally love this approach; it reminds me of the text-heavy games I grew up playing, and I enjoy the added precision. I’m probably in the minority on that, but the interface undeniably looks clean with a nice retro vibe regardless.
A word of caution before you go and download this. filter.tank can produce very loud and extreme frequencies that may damage hearing or equipment, so put a limiter after it.
filter.tank is available as a 64-bit VST plugin for Windows. The download is about 150 KB and doesn’t require you to sign up.
Download: filter.tank (FREE)
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Last Updated on March 9, 2026 by Tomislav Zlatic.



