McIntosh C32 Owner's Manual page 20

AC power switch, no current is drawn which causes the
current sensing relays in the C 32 to turn off all AC power
to the system.
Special Output Switching
In addition to the OUTPUT MAIN jacks, two additional
pairs of output jacks, OUTPUT 1 and OUTPUT 2, are pro-
vided. These are individually switched from the front
panel pushbuttons SPEAKER/OUTPUT. The C 32 output
signal can be fed to two additional stereo power amplifiers
independent of the main system stereo amplifier. Alter-
natively, these outputs may be used to drive reverberation
devices, delay lines, etc. The SPEAKER/OUTPUT pushbutton
switches provide the voltage to control a SCR speaker con-
trol relay.
Power Supply
To minimize hum pickup—and thus improve signal to
noise ratio—the C 32 power transformer is triple shielded.
Shielding includes a copper strap, a silicon steel strap and
finally, a steel outer shell. The transformer output voltage
is fed to a full wave bridge with 5,000 microfarad filter
capacitors to provide the plus and minus 24 volts powering
the MONITOR AMPLIFIER. The plus and minus 18 volts
needed for low level and op amp stages is derived from the
24 volt supply and controlled with integrated circuit vol-
tage regulators.
Turn on Delay
The C 32 has transient free turn on and turn off charac-
teristics. A relay, time controlled by a transistor switch,
connects the output of the preamplifier to the output jacks.
The control to the transistor switch is derived from a long
time constant capacitor charging network that turns the
relay on approximately two seconds after the C 32 is
turned on. The same circuit has a short turn-off time con-
stant which turns off the relay before the preamplifier's
main power supply has had a chance to discharge.
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