| The CMS 1055 TRIPLE MODULATOR is
a multi-function Euro-Rack module based on the ARP 1005 MOD-AMP
module used in the ARP 2500. We call it the "Swiss Army
Knife" of the CMS Euro-Rack system.
The balanced modulator is a high
accuracy multiplier employing double wilson current mirrors.
The balanced modulator uses matched transistors in a differential
configuration to process all audio. The balanced modulator
is an exact replica of the balanced modulator used in the
ARP 2500.
Compared to the original, CMS
has improved the functionality considerably by coupling the
balanced modulator with a high speed voltage controlled mixer
for selection of the carrier source. The voltage controlled
mixer consists of 2 high quality ARP type VCAs that have their
outputs mixed together and fed into the balanced modulators
carrier input. The 2 VCAs also have have individual dedicated
outputs.
It has 4 inputs, 3 of which
are attenuated: CARRIER A, CARRIER B, AND MODULATION. The
signal input has an AC/DC coupling switch.
The simple look of this module
can be deceiving. This unit can function as a stand alone
balanced modulator but it also has several additional, extremely
innovative operating modes:
1 - VOLTAGE CONTROLLED
BALANCED MODULATOR -
VCO1 (or any audio source)
is patched to the signal input.
VCO2 is patched into the CARRIER
B input.
8V D.C. is internally normalized
to the CARRIER A input - NO JACK is inserted into the CARRIER
A jack.
The MOD control voltage input
coupled with the "mix control" will control the
amount of balanced modulation present at the main output
jack. It will be variable from no ring modulation to full
ring modulation.
2 - MORPHING BALANCED
MODULATIOR -
Use the above patch and insert
a third audio source or VCO into the CARRIER A input.
When 2 separate VCOs are fed into each carrier input,
amazing morphing textures are possible through voltage control
of the MOD input.
3 - THE SEVEN QUADRANT
MULTIPLIER -
The modulation input is capable
of running at audio frequency for very complex tonalities.
4 different VCOs or audio sources can be fed into the 1055
simultaneously creating a whole new palette of complex output
waveforms.
4 - VOLTAGE CONTROLLED
MIXER -
Two different signal sources
are patched into the carrier inputs. The signal input switch
is set to "DC". The main output provides the mixed
signal. The mix is controlled by the MOD input and the front
panel "MIX " control. The signal input switch,
in this case, provides an output for the voltage controlled
mixer by feeding 8V DC to the balanced modulator. There
must be no jack patched into the signal input. You can also
patch a control voltage into the signal input to control
the final volume of the mixed signals.
5 - VOLTAGE CONTROLLED
PANNING -
The 2 additional VCA output
jacks provide the ability to distribute 1 or even 2 sources
to 2 separate destinations. The input of CARRIER B is normalized
to whatever is patched into the CARRIER A jack. This permits
easy patching of a single source to both carrier inputs
to facilitate panning. The panner will operate at audio
frequency so yes, AMPLITUDE MODULATION PANNING is also possible
with the 1055.
6 - ADDITIONAL CURRENT
MIRROR VCA -
The balanced modulator can
be used as a stand alone VCA. There are actually 3 ways
to do this. Here is one of them. The audio is inserted into
the signal input with the switch set to "AC".
The control voltage is inserted into the CARRIER A input.
The "MIX " knob is set to "A".
7 - MULTIPLE BALANCED
MODULATOR OUTPUT WAVEFORMS -
The signal input is provided
with a switch for input coupling. In addition to the VC
mixer function, this switch is used to provide more waveform
output options when processing audio signals through the
balanced modulator. Additionally, the CARRIER A input is
DC coupled while the CARRIER B input is AC coupled as an
alternative. Combining different AC/DC input combinations
provides a wider selection of balanced modulator output
waveforms.
8 - WHO KNOWS WHAT ELSE
-
There are probably other uses
for the CMS 1055, not yet discovered. That is the beauty
of modular synthesis.
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