Table of Contents
Advertisement
Installation
Unpacking
Upon unpacking, inspect the
amplifier. If you find any damage,
notify your supplier immediately.
Only the consignee may institute a
claim with the carrier for damage
incurred during shipping. Be sure
to save the carton and all packing
materials. Should you ever need
to ship the unit back to Crest, one
of its offices, service centers or the
supplier, use only the original facto-
ry packing. If the shipping carton is
unavailable, contact Crest to obtain
a replacement.
Because of the complexity of the de-
sign and the risk of electrical shock,
all repairs must be completed only
by qualified technical personnel.
Mounting
The CPX 4 amplifier will mount in
standard 19" racks. Rear mounting
ears are also provided for addition-
al support, which is recommended
in non-permanent installations like
mobile or touring sound systems.
Operating Precautions
Make sure the mains voltage is correct and the same as that printed on the rear of the amplifier. Damage caused by connect-
ing the amplifier to improper AC voltage is not covered by any warranty. See the Connecting Power section for more informa-
tion on voltage requirements.
Remember to have the gain controls turned down during power-up to prevent speaker damage if there is a high signal level at
the inputs. Whether you buy or make them, use good-quality connections, input cables and speaker cables, along with good
soldering technique, to ensure trouble-free operation. Most intermittent problems are caused by faulty cables.
Consult the Wire Gauge Chart to determine proper gauges for different load impedances and cable lengths. Remember that
cable resistance robs amplifier power in two ways: power lost directly to resistance (I
impedance, thereby decreasing the power demanded of the amplifier. Also, make sure the mode switch is correctly set for the
desired application. See Sections on Stereo, Parallel and Bridged Mono Mode for more information.
Make certain that there is enough space around the front and rear of the amplifier to allow the heated air to
escape.
Suggestion: In racks with closed backs, allow at least one standard-rack-space opening for every mounted power
amplifier.
Connecting Power
The CPX 4 amplifier power require-
ments are rated at 1/8 power (typical
music conditions) and 1/3 power (ex-
treme music conditions). The maximum
power current draw rating is limited
only by the front panel circuit breaker.
Consult the specifications in the Specifi-
cation section for figures on the current
that each amplifier will demand. Make
sure the mains voltage is correct and is
the same as that printed on the rear of
the amplifier. Damage caused by con-
necting the amplifier to improper AC
voltage is not covered by any warranty.
Therefore, be sure to set the line voltage
selector switch for the voltage in your
area.
Always turn off and disconnect the amplifier
from mains voltage before making audio
connections. Also, as an extra precaution, turn
the attenuators down during power-up.
5
Cooling Requirements
The CPX 4 amplifier uses a forced-air
cooling system to maintain a low,
consistent operating temperature.
Air is drawn into the amplifier by
fan(s) on the rear panel, courses
through the cooling fins of the tun-
nel-configured channel heat sink(s),
and then exhausts through the front
panel grille. If either heat sink gets
too hot, its sensing circuit will open
the output relay, disconnecting the
load from that particular channel.
The CPX 4 utilizes one common heat
sink and a single fan, but retains the
separate circuitry. NOTE: Maintain
an adequate air supply at the back
of the amplifier and enough space
around the front of the amplifier to
allow the cooling air to escape. If
the amp is rack mounted, do
not use doors or covers on the
front of the rack; the exhaust
air must flow without resistance.
If you are using racks with closed
backs, use fans on the rear rack panel
to pressurize the rack and ensure an
ample air supply.
2
R loss), and by increasing the total load
Advertisement
Table of Contents
