The Square wave fuzz is a unique vintage style fuzz originally made by Univox. It has a much more squashy nature to it, and sounds relatively similar to a fuzz face, but not quite. Instead of two silicon transistors, one is replaced with a JFET for a different sound.
The dist control is a rather strange one- it actually works similar to the filter knob on a rat, and is essentially cutting/choking frequencies. So when turned counter clockwise, it cuts a lot of signal and accentuates a lot of high end fizzle, when dialed back, a lot more gain and low end are pronounced.
The 3 way clipping toggle allows for a wider range of sounds as well- there is a stock silicon mode for that harsh, aggressive clipping that results in that meaty saturation, there is a vintage mode that adds a lot of compression, and gives this pedal a much more sputtery, fuzzy nature. Lastly middle position removes the clipping diodes for a blown out, loud, nasty fuzz sound.
