In the words of Mythos Pedals:

This circuit began its life as a clone of an Alan Yee Fuzzy Nuts which was supposedly used by Wilco’s Nels Cline. After years of production and tweaking the circuit has pushed beyond these initial clones to offer up more gain and volume while also reducing the noise. This simple one knob unit lives in your guitars volume and tone controls. The Golden Fleece cleans up better than almost any other fuzz out there and the single knob on the unit is a master volume control. The unit has a very balanced tone that doesn’t shift your guitars sound just offers a biting, yet full sound that would work for a variety of musical styles.