Keeley Psi Fuzz
The Psi Fuzz is basically a Big Muff Pi clone, with a couple of modifications. Although some of the old Muffs were constructed with op-amps, a good number of them were constructed with transistors. The folks at Keeley Electronics decided to put a twist on the formula, by including the op-amp and then passing the signal through a germanium transistor. The Psi Fuzz is a pedal for heavy rocking, capable of sludgy lows and bracing highs. It’ll take you from a freakout to a zoned-out metal dirge.
The Cream knob adds output, but what the Cream knob adds it will also take away. The noon position provides a nice, tight sort of fuzz that’s rich with Muff-like harmonics. Turn down the Cream for a darker, warmer sound that will seem to emerge from a mysterious and dark, fire-warmed cavern. It’s a good tone-colour generator for those moments when a totally clean signal would be inappropriate. Alternatively, crank up the Cream for the sort of thick, fuzzy distortion that cries out for drop tunings and slow dirges.
The Voice knob works in tandem with the Cream knob to brighten the high end or darken the low end, but it mainly works as a sort of EQ. In the middle is the neutral position and just a bit to the right or left of that will take the sound in new directions.