14
POWER GUARD
SGS
POWER GUARD
Meter Control Knob
The Meter Control Knob has three switch positions:
• LIGHTS OFF- the Meter lights will be off.
The Dual Meter will still respond to output
• WATTS- the Meter responds to all output and
the Meter Light is on unless controlled by
another unit as noted below
• HOLD- the Dual Meter needle will lock on
the highest peak in a series of peaks. When
a higher peak is reached, the needle will
hold that value. If no greater power level
is reached, the needle will lower its level
at a rate of approximately 6dB per minute
returning to a lower power peak or resting
position
Note that when in the WATTS or HOLD position,
the Meter Light will be powered On or Off by a
Preamplifier (or A/V Control Center) connected
by a Power Control Cable if that unit has Power
Control capabilities.
Power Control Knob
The Power Control Knob has three switch
positions:
• OFF- the MC901 will Power Off no matter
what signal may be received from a unit
connected by a Power Control cable
• REMOTE- the MC901 can be powered On
and Off by a Preamplifier or A/V Control
Figure 17– Front Knobs and LEDs
Power Guard
Screen Grid
Sensor™ LED
Power Guard
LED
Meter Control
Knob
Power Control
Knob
Center connected by a Power Control Cable.
See “Power Control” on page 8
• ON- this position will Power the MC901 On
Power Guard LED
Power Guard
®
continuously monitors input and
output signals and can dynamically adjust input
levels to insure maximum output while avoiding
harsh clipping or distortion. Patented Power
Guard
®
technology allows its circuitry to remain
completely outside the signal path unless needed.
When Power Guard is engaged, the effect is very
subtle especially when compared with clipping and
distortion of other overdriven Amplifiers.
The lower red LED indicates by flashing when
Power Guard
®
is engaged for the Solid State side.
Power Guard Screen Grid Sensor
(SGS) LED
Power Guard Screen Grid Sensor™ (SGS) helps
prevent premature Vacuum Tube failure by
monitoring the screen grid current in the KT88
output Vacuum Tubes. If the current becomes too
high, a circuit in Power Guard SGS™ is activated
which then dynamically attenuates the input signal
in real time to keep the Vacuum Tubes operating at
safe levels.
The upper red LED will flash when Power Guard
SGS is engaged in protecting the Vacuum Tubes.
