A Clockwork Orange; Vocoder Influence; Spectravox - Moog SPECTRAVOX User Manual

WENDY CARLOS AND BOB MOOG BEGIN TO EXPERIMENT
(Continued)
As it happened, Moog already had a design for a 10-band filter bank: it was the Moog 907 Fixed Filter
Bank, and it was one of the cornerstones of his modular synthesizer systems. A vocoder would need
two of these 907 Fixed Filter Banks—modified such that they each had individual audio outputs for
each filter band. These two filter banks were combined with 10 pairs of Moog 912 Envelope Followers
and Moog 902 Voltage-Controlled Amplifiers. A vocal signal into one filter bank (the "analysis" filter
bank) with an envelope follower connected to each filter band would capture the motions of the mouth
and lips with each filter band. An entirely different sound (the "carrier") would be put through the
second filter bank (the "synthesis" filter bank) and the level of each filter band would be controlled by
the corresponding signals from the analysis filter bank, mapping the tonal shapes of the voice onto the
carrier which was connected to the synthesis filter bank.

A CLOCKWORK ORANGE

This 10-band vocoder, built on and around the skeleton of the Moog modules Carlos was already
familiar with, had a distinctive futuristic and musical sound that the more expensive, higher-resolution
vocoders lacked: a warm, electronic tone animated by the human voice. With it, Carlos and her
production partner Rachel Elkind immediately got to work sketching out ideas for electronic "vocal"
pieces. Their first objective: Beethoven's Ninth Symphony.
While working on this vocoder treatment of Beethoven, Carlos was absorbed in the novel A Clockwork
Orange, and soon discovered that Stanley Kubrick was working on a film version. Through Elkind she
got in touch with Kubrick; he loved what he heard and decided to bring Carlos in to compose the rest
of the soundtrack for the film.

VOCODER INFLUENCE

By the late 1970s, the vocoder sound had begun to permeate the mainstream with works like
Kraftwerk's pioneering Autobahn (1974). Moog had developed a commercially available vocoder in
collaboration with Harald Bode—a premium signal processor with 16 filter bands—and vocoders began
popping up from other companies as well. Entering the 1980s, new genres such as electro and hip-
hop were exploding across the US with the vocoder as a key part of their signature sound: Hashim's
"Al Naafiysh (The Soul)," Cybotron's "Clear," and "Egypt, Egypt" by Egyptian Lover. Italo-disco artists
embraced it on records such as Casco's "Cybernetic Love," and experimental artist Laurie Anderson
saw a hit with her "O Superman" which featured the vocoder, her voice, and little else.
The sound of the vocoder never really left popular music—especially with the advent of digital
technology, which could provide as many filters as one wanted at a low cost. But the cold exactness
of a digital vocoder, while extremely intelligible, was brittle and couldn't bend and modulate alongside
other pieces of gear. We recommend the book How to Wreck a Nice Beach by Dave Tompkins,
published by Melville House Books (2011), for a deeper dive into vocoders.

SPECTRAVOX

Now, 52 years since the release of A Clockwork Orange, we have reached back into the past and,
influenced by Wendy Carlos and Bob Moog's 10-band vocoder design, created Spectravox. The
instrument is a bank of 10 filters with its filter frequencies set in accordance with those used for Homer
Dudley's Voder from 1939. An ancient piece of technology reborn, Spectravox pushes the topology of
the vocoder further by allowing all 10 filters to be shifted up and down the frequency spectrum. With
control over the resonance of the filters as well as a built-in LFO, carrier signal of a Moog oscillator and
noise source, and flexible routing, Spectravox is a fascinating new way to play with history.
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