Fairfield Circuity 20% More Slew Limiting Distortion Effects Pedal

Slew-Limiting Distortion with Attitude – The Fairfield Circuity 20% More Slew Limiting Distortion Effects Pedal

Explorations around a schematic found among old papers of mysterious origin, suspiciously similar to a datasheet sq/tri oscillator. All that was needed was to connect the dots.

A slew limiter smoothes out how quickly incoming voltage can change, limiting it to a fixed v/sec. slope. Since time and frequency are intrinsically linked, this acts as a steep, somewhat distorted low pass filter.

When it resonates, these fixed slopes become triangle wave oscillations, giving 20% more its unique sound. Input signals can overwhelm this oscillation, making for pseudo-wavefolding and synthetic distortion artifacts.

jfet clipping, sub and upper octaves, envelope follower, low pass gate; impressions, ideas, pleasures and pains

SPECIFICATIONS

Controls

• INPUT – ‘mu amp’ JFET preamp, lots of gain
• BLEND – mixes in a square wave / sub-octave copy of the signal
• VOLUME – output volume, gets very loud
• SLEW – slew limiter frequency
• FEED – slew limiter feedback
• LPG – low pass filter
• D – OCTAVE DOWN – clock division of the blended square wave, -1 or -2 oct
• U – OCTAVE UP – analog octave up, full wave rectifier
• E – ENVELOPE DESTINATION – routing of the internal envelope, either added to the (L)PG or (F)EED controls

Connections

• IN – 1/4″ instrument or line input
• OUT – 1/4″ output
• CV – versatile 1/4″ TRS CV/Exp port, see programming guide
• S – 1/8″ input
• CV over slew limiter frequency, v/oct
• 9VDC – 2.1mm centre negative tip, 20 mA (sags quite well)

Dimnesions

• Dimensions – 4.7″ x 3.8″ x 1.9″
• CV Input Range – 0 – 5V normal; 0 – 8V max
• Power Supply – 9VDC
• Current Draw – 20 mA @ 9.6 VDC

Manufacturer: Fairfield Circuitry MAS Distro
Model: FC-20M
SKU: I827222-N-1-WHXB

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