Switching On; Level Controls; Prc Indicators; Temperature Control - MC2 Audio E4-75 Owner's 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, the red A/P LED will go off.
PANEL CONTROLS AND INDICATORS

Level controls

These are analogue controls allowing precise level settings. Note that in 'BRIDGED' mode, both
level controls must be set to the same position.
Limiters
Each channel incorporates a high performance limiting circuit that prevents the outputs from
'clipping' when the maximum level is exceeded. They have been designed to be transparent to
signals below this level and the attack and release times have been optimised for them to be
unobtrusive when in operation.
Level Indicators
Each channel has an LED level 'bar', which shows green up to the -3dB point, then orange and
finally a red limit LED. Note the limit LED has a different response time to the others and with fast
transients, can be 'on' even though some of the lower level LEDs are not.
PRC Indicators (green LED)
These indicate when the PRC circuit, for the specific pair of channels, has been selected. (Either
manually via the switches on the rear panel or automatically via the impedance sensing circuit)

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 4 fans connected permanently with variable speed and a jumper link to enable them
from cold.
Normal dynamic signals will not cause the amplifier to overheat unless the ventilation
is inadequate. (See installation section and maintenance section.)
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