Technology (2)
Technology (1)
Technology (2)
Technology (3)
Modules (1)
Modules (2)
Modules (3)
Modular Ads (I)
Modular Ads (II)
Surrounding these core modules were various helper circuits and add-
ons. One of the most important and least appreciated were the CP3
four-input mixers, which typically were fitted under the oscillator
banks. This was where much of the timbre-shaping happened, because
you could use these to control the proportions of each oscillator and
waveform before filtering. There was no voltage control here, so
timbres were static. If you wanted to change them, you could only do
it by twiddling the mix knobs by hand. It didn't take long before
enthusiastic synthesists realised you could also control timbre
dynamically by patching oscillators through VCAs and ADSRs before
mixing. The results weren't always spectacular, but even today, this
degree of control is only available on a very limited number of
synthesizers. The later CP3A could also be used to combine modulation
sources, and adventurous programmers discovered it could be used to
add deliberate electronic feedback to sounds. This didn't create the
kind of shrill grungey scream you'd expect from guitar feedback.
Instead it added even more body and weight, and gave the patches that
sound now widely recognised as distinctively 'Moogy'.

Elsewhere, the modular included the usual features we'd expect from a
synthesizer today. The 903 noise source provided white noise (useful
for breathy chiffs, wind, surf and other special effects), as well as
offering a separate and distinct more rumbly pink-noise source. In
later modulars, this module was expanded to include simple static low-
and high-pass filters. The 905 offered spring reverb, making the
Moog the first synth design to include built-in effects, with the
difference that you could control the send and return levels with any
of the other modules. The Moog technical manual suggested that to
avoid hum and other interference-related problems, the reverb springs
were to be mounted well away from 'power supplies, motors and other
devices'. It was also a bad idea to place speakers too close to the
cabinet, as acoustic feedback with the springs could have cone-
ripping consequences. And as with all spring reverbs, a sharp thwack
with the hand would produce an apocalyptic-sounding 'sproing'.

Also in the original line-up was the 907 fixed filter bank. Based on
suggestions by Wendy Carlos, this was a primitive graphic equaliser
equipped with knobs instead of sliders. Carlos used the circuit to
simulate the resonant formants in acoustic instruments. Almost
everyone else either ignored it, or used it as a crude tone control.
It was later replaced by the 914, which was designed to do a similar
job, but was rather more polished internally.

Getting Ahead

That completed the line-up of the first set of modules, all of which
were available by 1967. The range was extended during 1968, and Moog
also took to offering pre-packaged modular systems for those who
wanted to buy an off-the-shelf product without weeks of research. As
far as most musicians and studios were concerned, these were the
beginnings of the true modular story. Although smaller collections
such as the Moog 10, Moog 12 and Systems 1 and 2 were available, the
most versatile all-in-one system was the imaginatively named System
3. This included all the basic modules plus some enhanced extras,
including the 911A dual trigger/delay, the 912 envelope follower and
the 984 four-channel mixer. The former made more sophisticated
envelopes possible by triggering a second envelope after a fixed
delay. The original and the delayed ADSR shapes could then be mixed
to create very complex modulation curves. The 912 created a varying
modulation level by tracking the loudness of an audio input, and also
provided an envelope trigger. The mixer was an unusual 4:4 matrix
mixer design with bass and treble and insert points for each channel.
If you had four speakers, you could now use your Moog for discrete
quadraphonic music.
The most important addition to the Moog range was the 960 step
sequencer. Arranged as three banks of eight voltage settings which
would be output in turn when the sequencer was stepped with a clock
pulse from a keyboard, or the internal clock oscillator, the 960
could be used to create a repeating sequence of modulation voltages.
The bottom bank could also be used to control the duration of each
step. And there were various options that controlled the length of a
sequence and the creation of gate signals for the envelopes. The 960
was often supplied with a couple of moderately baffling extras. The
961 interface converted voltage triggers to and from Moog's quirky S-
Trigger system, and also included some audio-triggering features. And
the 962 sequential switch module could switch between two of the
banks in turn to create a single 16-step sequence.