The Kn² Octave Fuzz VST plugin is based on a late-’70s box that, for lack of a better way to describe what it does, was simply named after its color.

Capitalizing on the already square-wave-like nature of heavily distorted guitar signals, it uses minimal digital circuitry to generate same-octave and two-octaves-down signals that track the guitar input. These generated signals are then fed through an envelope follower to restore the original dynamics and mixed together to produce the final output.

The result: a gnarly, gated, heavily distorted tone with loose sub-octave tracking that tends to wander all over the place—unless you carefully play around the 12th fret using your neck pickup and roll off the tone. In other words: great success!

Why wasn’t the original distorted signal mixed into the output? Why two octaves down and not one? Or why not both, for that matter?
All excellent questions. Beats me.

The model features two controls: Output and Blend. While the Output control adjusts the output level in a rather predictable manner, the Blend control mixes in the sub-octave signal - but backwards: turning it clockwise results in less sub-octave. Technology. Go figure.