Fairfield Randy`s Revenge Data Sheet
F A I R F I E L D C I R C U I T R Y
R M 0 0 0
V O L U M E
M I X
L P F
S Q S I
L O H I
F R E Q
RANDY’S REVENGE
Ring Modulator
OVERVIEW
Ring modulation at its nest, in a considerably small package, powered by your typical 9V power supply, all analogue, hand stamped,
pure sine wave oscillator, low-pass ltered with a touch of class and
apparently musical. These are the requirements of warp speed space
travel; a regular occurrence when dealing with Randy’s hardware.
The lower oscillator frequencies create rich trem/vibe effects, excruciatingly slow or chopped up rhythmic avours. As the frequency
goes up, thick bells, tuned intervals, low-delity synth-like effects
are only the beginning. Experimenting with the low-pass lter cutoff
frequency and the dry/wet mix will yield tones as strange or subtle
as desired.
Featuring expanded control voltage (CV) capabilities that allow for
interactions beyond the simple stacking of effects, Randy can be
used to control and be controlled by other CV capable devices. The
stereo CV is switch-programmable for use with an expression pedal
or as a 2-channel CV port. Both the oscillator and low-pass lter
frequency are voltage-controllable. The internal oscillator is also
available as an output, turning Randy into a stand-alone voltagecontrolled oscillator (VCO).
CV interface
Plenty of output volume
Dry/wet signal mix
Low-pass lter frequency
Instrument level inputLow impedance output
9 VDC
Square/sine waveshape
Hi/lo frequency range
Oscillator frequency
TECHNICALS
NOTES ON POWERING
- input impedance 1 MΩ
- output impedance 1 kΩ
- power supply 9 to 9.6 VDC
IN
- current draw 85 mA
PHYSICALS
- true true bypass
- 1/4” mono input/output jacks
CV
- 1/4” stereo CV jack
- 2.1mm DC connector
- 4.7” x 3.8” enclosure dimensions
THE VOLTAGE-CONTROLLED OSCILLATOR
The VCO generates a low distortion sine wave whose frequency
can be controlled in many ways. The HI/LO switch sets the operating range of the VCO; LO for 0.5Hz - 45Hz, HI for 18Hz - 2.4kHz.
The FREQ control sets the oscillator’s rate within the selected
range. The shape of the waveform sent to the analogue multiplier
is selected with SQ/SI switch; SQ for square, SI for sine.
THE FOUR-QUADRANT MULTIPLIER
The effect commonly known as ring modulation is simply the
multiplication of two signals. The result of which is the sum and
difference of all frequencies involved. Ideally, this also means
that none of the original signals should be present in the output.
In reality, all multipliers exhibit some degree of bleedthrough. As
is the case with noise in general, bleedthrough will become more
audible when higher gain is involved.
THE VOLTAGE-CONTROLLED LOW-PASS FILTER
Located after the multiplier, the second order low-pass lter
affects only the modulated signal, not the clean one. This proves
useful in taming the incoherent mess generated by the multiplication. The LPF control sets the cutoff frequency of the lter.
FREQ
VCO
HI/LO
MIX
VOLUME
OUT
SQ/SI
LPF
THE INPUT AND OUTPUT SECTIONS
When engaged, the input is rst buffered
by a discrete JFET gain stage, providing an ideal interface for instrument level
sources and a characteristic tone. The MIX
control is quite simple, ranging from fully
dry to fully wet. The output level is set
with VOLUME control. Unity gain is obtained
when the control is set around noon. When
disengaged, the signal is true bypassed.
THE CV JACK
By default, the control voltage (CV) jack
is to be used with an expression pedal to
control the oscillator’s frequency. Expression pedal must follow the “wiper to tip”
standard. It is possible to do much more
with the CV jack by understanding the
micro-switches located inside the pedal.
Please refer the Programmer’s Reference
Manual for more information.
Randy’s Revenge was designed to
operate using your typical centre negative, regulated 9-9.6 VDC
power supply. The pedal is protected against reversed polarity and
overvoltage conditions. Always check
your power supply for proper voltage
and polarity before connecting. There
is no battery connection inside the
pedal.
EXTENDED WARRANTY
Faireld Circuitry will repair or
replace any malfunctioning product
for a period of 2 years after purchase date. Problems resulting from
modications or misuse may cancel
this warranty. The owner will cover
all shipping expenses. This warranty
applies only to original owner of the
product. Proof of purchase might be
required.
In short, the best thing to do is to
contact us as soon as possible with
a description of the symptoms, even
if the warranty is expired.
UNIQUE & ROBUST
MADE IN HULL, QUÉBEC
FAIRFIELDCIRCUITRY.COM
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