LED INDICATORS
The LED indicators can be used to monitor system operation and identify common problems.
POWER: A single green indicator, on left side of AC power switch.
Normal indication: AC switch ON: indicator will illuminate.
If no indication: Check AC power cord and AC outlet. Check rear panel circuit breakers.
CLIP: red, to the left of each Gain control.
Normal indication: illuminates whenever the amplifier is driven beyond full power. The LED's brightness indicates the
amount of distortion. Distortion that causes only brief flashing may not be audible.
During muting, the indicator fully illuminates. This occurs during normal "On-Off" muting.
Abnormal indication:
•Bright red illumination while the amp is being used indicates either thermal muting or a shorted output.
•If the amplifier overheats, the fan will run at full speed, and operation should resume within one minute. Allow the fan to
run, and make sure the amplifier ventilation is adequate.
•A shorted or overloaded output circuit will cause excessive Clip flashing and possible overheating.
•If distortion is audible without a Clip indication, the problem is either before or after the amplifier. Check for damaged
speakers or overloaded signal source. The amplifier Gain control should be in the upper half of its range to prevent input over-
load.
SIGNAL: yellow, to the left of each Gain control.
Normal indication: illuminates when the input signal exceeds -35 dB. As signal approaches full power, the indicator will
illuminate continuously.
If no indication: check Gain settings and increase Gain if necessary. Check input connections and audio source for signal. If
the Clip indicator illuminates with little or no Signal indication, check the output wiring for shorts.
Abnormal indication: If the Signal indicator illuminates with no signal input, there may be system oscillations or some
other malfunction. Disconnect the load and fully reduce the Gain. If the signal indicator remains on, the amp may need servic-
ing.
PROTECT: red, on the right side of Gain control group.
Normal indication: illuminates when the amplifier goes into protective muting. Under normal operation, this indicator will
not be illuminated.
Abnormal indication: If the Protect indicator illuminates, the amplifier is in protective muting. Leave the Power On to allow
the fan to cool the amplifier. Check the rear panel circuit breakers; if either is tripped, reset it by pushing on the center of the
control. When the amplifier has cooled sufficiently, the Protect indicator will extinguish and normal operation will resume.
Note! If both rear panel circuit breakers are tripped, the Protect indicator will not be illuminated.
Indicators and Gain controls.
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