Sequential PROPHET-600 - SYNTHESIZER CONTROLS

SYNTHESIZER CONTROLS
7-0
INTRODUCTION
As
explained
in
the Preface,
the
Prophet-600
actually contains six synthesizers,
termed "voices." Only one
voice
is depicted on the front panel because, except
for the
LFO,
the controls "patch" all six voices identically—which makes them sound alike.
The Prophet-600 fits into
the tradition
of
voltage-controlled analog synthesizers.
To
understand these instruments it has proven useful to identify three basic functions:
audio sources, modifiers, and controllers. Briefly, controllers create the control
voltages (CVs) which determine the pitch of the audio sources, or the filtering or
attenuation effect of the modifiers. Each voice contains several of each type of
function, which are represented on the block diagram, Figure
7-0.
On each voice, there are three audio sources: OSC A, OSC B, and the filter, if it is
adjusted
for self-resonance. The audio level and timbre can be modified by the mixer,
filter
(when not in self-resonance), and amplifier. The keyboard is the most conspicu-
ous
controller, since
it
issues the six separate KYBD CVs which determine the
oscillator
pitch on each voice. The MASTER TUNE knob and PITCH wheel provide two
separate CVs which control all of the oscillators. And the
two envelope generators
must each be regarded as a controller of its
respective
filter or
amplifier.
Considering
the
modulation systems, the LFO is a
controller,
as is OSC
B when
it is used
with
POLY-MOD.
CM600A 12/82
7-1