Evil Filter

Psycho HP/BP/LP filter with a sleek, laser etched enclosure. Can be pushed past the limit into octaves up, down, and folding envelopes. Its medical grade IC chip creates a hyper precise filter that sounds like no other. The Evil Fuzz takes signals into a much darker dimension, offering an inverted compression toggle to push sounds even further into the depths. Using the CV/Expression input, you can control the filter cutoff frequency with an expression pedal or synthesizer.

https://deathbyaudio.com/products/evil-filter-1