CX-A4
I
NSTALLATION AND OPERATION MANUAL
2
1 Safety
Notes
•
Do not expose the unit to water or moisture
•
Do not expose the unit to naked flames.
•
Do not block or restrict any air vent
•
Do not operate the unit in ambient temperatures above 35
o
C
•
Do not touch any part or terminal carrying the hazardous live symbol ( )
while power is supplied to the unit.
•
Do not perform any internal adjustments unless you are qualified to do so and
fully understand the hazards associated with mains operated equipment.
•
The unit has no user serviceable parts. Refer any servicing to qualified service
personnel.
•
If the moulded plug is cut off the lead for any reason, the discarded plug is a
potential hazard and should be disposed of in a responsible manner.
For more detailed information refer to the rear of the manual.
2 General
The CX-A4 is a four-channel power amplifier with a maximum channel output of 120 watts
into 4 ohms. The unit features extremely low distortion and low noise together with a high
slew rate. Full circuit protection is provided and the load is disconnected if the heat sink
overheats or any DC is detected at the output. A five-second switch-on delay operates to
avoid any switching thumps or other extraneous signals reaching the speaker system.
All four input amplifiers are balanced and connect via 3 pin XLR type connectors with
adjacent level controls, all mounted on the rear panel. Input signal routing switches are
provided and allow the unit to operate in many configurations whilst retaining simple input
connections.
The CX-A4 amplifier can be used with up to two optional plug-in two channel VCA
modules to provide remote level control. Each plug-in module can operate as two
individual attenuators or can be linked to operate as a stereo pair with one remote level
control.
3 Installation
The CX-A4 is suitable for mounting in a standard 19" equipment rack and occupies two
units of rack space. Sufficient ventilation must be provided for the unit. The amplifier
draws cool air through the front panel and exhausts through the right side and care must
be taken not to obstruct the airflow otherwise the unit may intermittently turn off due to the
built-in thermal protection. Applications, which require long, sustained operation at high
power levels, should allow a 1U space above and below the unit. The unit is 325mm deep
but a depth of 400mm should be allowed to clear the connectors.
4 Input
Facilities
All four inputs are balanced and use 3 pin XLR type connectors. All inputs are wired to
the standard convention of pin 1 ground, pin 2 in-phase, pin 3 reverse phase, with the
shell of the connector connected to the chassis. If the unit is operating in a location which
has a high level of electrical or magnetic disturbance or is close to a TV or radio
transmitter, we suggest that the input cable screen be connected to the shell of a metal
XLR type connector. If the signal is from an unbalanced source, connect pin 3 to pin 1
(ground) inside the XLR type connector and use pin 2 as hot.
Every input has a level control adjacent to the respective XLR type connector. Input
switching is provided on input channels 2 to 5 allowing a wide variety of input routing
configurations. See the schematic diagrams showing details of various routing
possibilities.
With all input switches depressed, the unit operates as four independent amplifiers.
Three stereo pairs, driven from one stereo source and four channels driven from one
mono source are also possible together with a combination of the two by suitably
configuring the input routing switches.
15-07-02 V9
