What does “expressive double filter fuzz” even mean? Well, there are two filters pushed by a fuzz that opens up to more control via an expression pedal jack.
PRE (P) controls the amount of FUZZ pushing into the filters. More volume pushes the filters to open up faster.
FILTER 1 sweeps the first filter from a gulpy, swallowed up sound to a fly buzzing in your brain grind. You can turn this filter OFF via the TOGGLE, allowing the FUZZ to hit FILTER 2 unobstructed.
FILTER 2 (F2) sweeps an envelope filter. As one moves the F2 pot clockwise, he/she/they can hear the “vocal/vowel quality” of the filter change. With more volume from PRE, the envelope opens faster.
VOLUME (V) controls the output level.
When the left MOMENTARY FOOTSWITCH is fully depressed and held down, the frequency range of the envelope filter (F2) immediately changes. Think of a wah going from toe-down to heel-up via a footswitch.
The EXPRESSION PEDAL overtakes the PRE (P) pot and allows one to control how much fuzz hits the filters. Almost turns the pedal into a wah that changes the vocal quality and funk/feel of the overall sound. Get weird with it!