Advanced Features And Options; Protection Systems; Power Circuit Breaker; Proportional-Speed Or 3-Speed Fan - Crown CH Series Operation Manual

CH and CL Series Power Amplifiers

4 Advanced Features

and Options
Operation Manual
NOTE: For detailed information about these
Crown amplifier features, please consult
the Crown Amplifier Application Guide,
available on the Crown website at
www.crownaudio.com.

4.1 Protection Systems

CH and CL Series amplifiers are protected against
shorted, open or mismatched loads; overloaded
power supplies; excessive temperature, chain
destruction phenomena, input overload damage and
high-frequency blowups. They also protect loud-
speakers from input/output DC, large or dangerous
DC offsets and turn-on/turn-off transients.

4.1.1 Power Circuit Breaker

A back-panel push button is used to reset the circuit
breaker that protects the power supply. Available in
CH1, CH2, CL1 and CL2.
4.1.2 Proportional-speed or 3-speed
Fan
In the CH1, CH2, CL1 and CL2, a proportional-
speed fan directs the airflow through the amplifier
for cooling. In the CH4 and CL4, a 3-speed Fan-On-
Demand does the same thing.
4.2 Advanced Features
®
4.2.1 BCA (CH4 and CL4 Only)
BCA (Balanced Current Amplifier) is Crown's pat-
ented, cutting-edge technology that gets more
power out of an amplifier with less waste than was
ever before possible. A completely new adaptation
of standard amplifier design, Crown's BCA "switch-
ing" amplifier design provides for high output,
exceptional reliability and nearly twice the efficiency
of typical amplifier designs.
While switching designs have been used success-
fully in other applications, these designs were never
before suitable for use in precision, high-power
audio amplifier applications. Crown's BCA technol-
ogy changes that, with a totally new paradigm for
amplifier design that represents the future of profes-
sional amplifiers.
With their superior efficiency, BCA amplifiers can
help to keep power requirements lower, while still
providing excellent audio reproduction. And Crown
BCA amplifiers are tough—easily handling very
low (and highly reactive) load impedances, even
under extreme conditions. In fact, Crown BCA amps
have far out-performed competitive amplifiers in
tests where the amplifier was run as much as 12 dB
into clip for extended periods of time.
4.2.2 Switching Power Supply with
PFC (CH4 and CL4 Only)
Crown's new Switching Power Supply with PFC
provides a range of benefits over both non-switch-
ing and conventional switching power-supply
designs.
Typical non-switching power supplies require large
transformers in order to produce the required power
at the output stage. These transformers must be
large to absorb the waste that occurs when operat-
ing at 50 to 60 Hz (standard AC supplied by the
power company).
By contrast, switching power supplies can operate
with a much smaller (and lighter) transformer
because they first convert the AC up to a much
higher frequency, thereby reducing waste.

4.3 Options

4.3.1 Input Sensitivity

Input Sensitivity is factory set to1.4V for each chan-
nel. With this setting, a 1.4V input signal will drive
the amplifier to full power into an 8-ohm load when
the Level Controls are turned to maximum. This set-
ting works best when the amplifier is being driven
by equipment with a +4 dBu output. Optionally, the
Input Sensitivity for each channel can be individu-
ally set to either 0.775V or 26 dB. To have the input
sensitivity changed on your amplifier, contact an
authorized Crown Service Center

4.3.2 Crown SST Modules

Crown optional SST (System Solution Topologies)
modules were specially designed to improve the
fidelity and versatility of your audio system. They
feature a variety of professional signal routing and
filtering capabilities, with active crossovers that
allow the audio signal to be split and sent to auxil-
iary amplifiers. Your amplifier may have come with
an SST module already factory-installed, or your
choice of SST modules can be easily added to the
amplifier by any authorized Crown Service Center.
For information on wiring and configuration of
amplifiers equipped with an optional Crown SST
crossover module, please refer to the SST Cross-
over Reference Manual included in your literature
package.
Refer to the following descriptions for an overview
of available Crown SST crossover modules. Crown
plans to release additional accessory plug-in mod-
ules offering a range of advanced features and capa-
bilities. Watch for new releases.
page 19