The front panel POWER ON pushbutton must be
left in the off or out position for this automatic con-
trol to operate. When the rear panel slide switch is in
the manual position, only the front panel pushbutton
has control.
POWER SUPPLY
To minimize hum pickup and thus improve signal
to noise ratio the C 29 power transformer is triple
shielded. Shielding includes a copper strap, a
silicon steel strap, and a steel outer shell. The
transformer output voltage is fed to a full wave
bridge rectifier with 3,000 microfarad filter
capacitors to provide the + 24 volts for powering the
headphone amplifier and the plus voltage regulator
and - 2 4 volts for the minus regulator. The ± 1 8
volts needed for low level and operational amplifier
stages is controlled with integrated circuit voltage
regulators.
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