Moog Satellite Service Manual

MUSIC INC.tr^
Academy Street (P.0 Box 131)
Witliamsville. N Y. 14221 • phone (716) 633 22lU)
September 20, 1972
SATELLITE SYNTHESIZER CIRCUIT. DESCRIPTION &
GENERAL TEST PROCEDURE
CIRCUIT FEATURES .
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The sound producing chain of the Satellite Synthesizer .
consists of an oscillator that produces both sawtooth and
rectangular waveforms, a band'pass filter, a lev; pass filter,
•' anci a variable gaih amplifier. All four of these circuits in
the sound producing chain are voltage controlled. The remainder
of-.the circuitry-is devoted to producing appropriate control
vo.tages. The .keyboard circuit produces one pitch control
vo;tage whose magnitude depends on which key is depressed, and
a t rigger voltage which is on whenever any of the keys is de¬
pressed. The modulating oscillator produces triangular and
square waveforms for modulating the oscillator and the filters.
Two contour generators produce voltages that rise and then fall
each time a key is depressed. One of thpse sweeps one of the
filters, while the other sv/eeps the amplifier. A resistor matrix
determines the average values of the voltage-controlled para¬
meters. The power supply delivers + 13 volts unregulated, and
+ 9 volts regulated.
The resistor matrix has fifteen input columns and twelve
output rows. A column is on when + 9 volts is applied to it,
and it is grounded when it is off. The two left-most columns
are connected to the "two octave" and "one octave" switches
respectively. They shorten the contour times and raise the
.filter frequencies when they are on. The remaining columns u
are the quickset voices. Only one of these is on at a time. ,
The rows are fed to low impedance points in the circuitry.
Of ’the twelve matrix output rows, eight supply control currents
.for continuously variable parameters, while the remaining four
supply switching current to determine circuit states.
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DESCRIPTION OF CIRCUITRY ON LARGE BOARD • [
The large circuit board which mounts underneath the key¬
board contains most-of the Satellite circuitry. All connections
to this board are made through two Molex connectors. Looking
at the board from the component side with the connectors along
the top edge, _the left hand connector is designated "A" and
the right hand connector is designated "B". The pins are
numbered from 1 to 24 starting with the left hand pin on each
connector. Drawing 08-005 is a schematic diagram of this
boar*l. The designations used in the discussion of the circuitry
are yhose shown on drawing 08-005. , _. . .. . ••
' . •' 7 t'f.

Moog Satellite Specifications

General

Brand	Moog
Model	Satellite
Category	Synthesizer
Language	English