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In general, “synthesis” refers to the generation of sound through a group of
amplified circuits over which the programmer/performer has power to change
volume, pitch, timbre and articulation. The Minimoog Voyager is based on what is
called “subtractive synthesis”. This method of synthesis employs a harmonically rich
(think bright-sounding) source material, and then removes frequency components
to create the desired sound. The basic components of subtractive synthesis and
their definitions follow:
Oscillator
: A circuit that electronically “vibrates”. When used as a sound source, an
oscillator is the electronic equivalent of a vibrating reed, or string. When amplified,
an oscillator produces a pitched sound whose frequency is determined by one or
more control voltages (see below for more info). Changes to these voltages
correspond to changes in pitch. An oscillator’s vibration can have different shapes
or waveforms, which are described below. The Voyager has three oscillators.
Waveform
: The shape of an oscillator’s vibration. This determines its timbre.
Commonly used waveforms in subtractive synthesis are sawtooth, triangle, square,
or rectangular. Different waveforms have different timbres. A sawtooth has the
greatest number of harmonics, and sounds bright and buzzy. A square wave has
only odd harmonics, and sounds bright, but hollow, like a clarinet. A rectangular
wave can vary in shape, but typically has a bright but thin sound, and a triangle
wave’s harmonics are so low in amplitude that it sounds muted and flutelike (figure
6).
Mixer:
A circuit for combining multiple sound sources or signals. The Voyager’s Mixer
allows you to select and set the level for up to 5 different sound sources.
