Operation; Prc Indicators; Temperature Control; Switching On - MC2 Audio E Series Instruction Manual

Operation

SWITCHING ON

At 'switch-on' the protection circuit will initially activate whilst the circuits stabilise. Assuming no faults
are detected after a few seconds, only the 'POWER' LED and active "Link" LEDs (and 'SIGNAL' indicators
if signal is applied) will be illuminated.
PANEL CONTROLS AND INDICATORS
Level controls
These are analogue controls allowing precise level settings. Note that if channel link LEDs are
illuminated, some controls may not operate – please refer to previous section explaining the operation of
the Input Link Switches.
Signal Indicators (3 Green LEDs)
These are active from a minimum output level of approximately 10 Watts and are only an indication of
signal level.
-3dB Indicators (yellow LED)
These are active when the signal is 3dB below the limiting level.
Limiter/OCM Indicators (Red LED)
The E Series amplifiers incorporate signal limiters, which are preset to prevent clipping with high levels
of drive. The red LEDs on the front panel illuminate to indicate operation of the limiters. The output
current monitor (OCM) may activate to limit the output current of the amplifier channel - this can occur
even if the amplifier has not reached clipping point. The OCM indicator can operate independently of
the bargraph meter. Typical conditions that may trigger the OCM circuitry would be too low a load
impedance, or high subsonic or VHF levels.
PRC Indicators (green LED)
These indicate when the PRC circuit for that specific channel has been selected with the rear panel
switches.

Temperature Control

The cooling fans respond to temperature sensors within the unit to maintain a safe operating
temperature. In the event of excessive temperature, the protection circuit will operate, disabling the
output. The red 'AUDIO-PROTECT' (A/P) LED will indicate this condition. (See fault indicator.)
There are 2 fans connected permanently with variable speed.
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