This Nautilus is Madbean's modernized version of the Mutron III envelope filter, made famous by countless funk guitarists and Jerry Garcia. There are a huge number of sounds inside this thing, and I really couldn't demonstrate them all properly in such a short video, though I did my best to explain how the controls work. The pedal's sound can vary greatly depending on the setting, which rewards experimentation but also meant there was a lot to keep track of for the demo.
I also show how it reacts to a compressor or boost in front later in the video.
My one issue with the pedal is that the gain control has far too small a useable sweep. I might swap it out for a different taper or value. It's very, very touchy and only the last 1/3 gives any effect (or even gets above unity volume). Otherwise, it was a comfortable and even easy build. Just be sure not to skimp on the vactrols.
Gear:
Don Quixotecaster (Reilander Vintage Strat pickups)
Tone King Imperial
George L's cables
Nautilus
Bearhug compressor
fingers