Fairfield Circuitry ~900 Fuzz
INPUT - preamp input level
FUZZ - interstage level
BIAS - second stage bias and gain
VOLUME - output level
The ~900 is a ferocious fuzz pedal featuring two cascading JFET gain stages. The ~900 is a spiritual successor to our discontinued Four Eyes Fuzz, having a similar fuzz circuit. This pedal has a very wide range of gain, brought to you by four interactive controls: INPUT, FUZZ, BIAS, VOLUME.
The INPUT section is a 'mu-amp' design. The INPUT knob controls the level going into this first gain stage - you can go from clean with lots of headroom, to completely slammed and distorted - and everything in between.
The FUZZ knob controls the level going into the second JFET gain stage. This section is very dependent on the level of the INPUT.
The BIAS knob adjusts the bias of the second gain stage. This gives control over the saturation symmetry, and can also allow gating when turned up high enough. The BIAS knob is especially interactive with the FUZZ knob.
The VOLUME controls the master volume output. This pedal has a lot of gain to offer
and can get quite loud.
The ~900 is an overall very versatile fuzz pedal. It stacks well with other pedals and is friendly to all sorts of instruments and signal levels. The INPUT especially will dictate how the pedal responds. At lower INPUT levels, the FUZZ will have a wide range of tones and interact heavily with the BIAS knob. When the INPUT is raised high, the FUZZ and BIAS will be a bit less responsive - but at that point you will be experiencing a thick wall of distortion/fuzz.