General Information; Connections - MC2 Audio E4-75 Owner's Manual

GENERAL INFORMATION

Your E4-75 power amplifier utilises proprietary designed load impedance sensing output
circuitry, which enables the amplifier to drive the high voltage swings associated with speaker
impedances of 8 ohms and above, but automatically switches to a high current/medium voltage
output required by 4 ohm loads.
Fan speed is varied as required to keep the amplifier within its temperature limits. Signal limiters
are included to protect speakers from clipped signals.
The amplifier includes full DC and short circuit protection to ensure trouble-free service even in
'harsher' environments.
The E SERIES introduces three user-controlled features previously not seen on MC
amplifiers:
Bar LED level indicators on the front panel.
Power reduction control (PRC)
User-settable gain/sensitivity (internal)
Power Reduction Circuit (PRC) and Impedance Sensing
There are two PRC circuits in the E4-75: one for channels A & B and one for channels B & C.
When the amplifier is to be used with 4 ohm speakers (or bridged mono into 8 ohms) or if you
want to reduce the maximum power to protect the speakers, then the PRC can be selected via the
switches on the rear panel.
Whenever an audio signal of medium amplitude is present on any channel and, if the speaker
impedance on any of the channels is less than 5.5 ohms, then the Automatic Impedance
Sensing circuit will set that pair of channels to the 4 ohm position.

CONNECTIONS

NOTE THAT ALL AMPLIFIERS BEFORE SERIAL NUMBER 7E70004 HAVE A DIFFERENT
WIRING CONFIGURATION FOR THE INPUT AND OUTPUT SOCKETS. THIS WILL ONLY
AFFECT THE 'LINKED' OR 'BRIDGED' MODES OF OPERATION.
INPUTS
The inputs are made via 3-pin XLR connectors, which are electronically balanced and should be
connected via a high grade twin core screened cable, as follows:-
Pin 1 - Screen (see note)
Note: +ve and –ve denotes the phase of the signal
Pin 2 - +ve signal (hot)
8
Pin 3 - -ve signal (cold)
2
Audio