Crown ce-4000 Guía Del Usuario

CE 4000 Power Amplifi er

NOTE: For detailed information about 
these Crown amplifi er features, please 
consult the Crown Amplifi er Application 
Guide, available on the Crown website 
at www.crownaudio.com.

Your Crown amplifi er provides extensive pro-
tection and diagnostic capabilities, including 
built-in anti-clip limiters, amplifi er fault protec-
tion, and switchable high-pass fi lters.

5.1.1 Anti-Clip Limiters
Your Crown amplifi er has built-in Anti-Clip 
Limiters which offer a degree of protection 
to your loudspeakers. The Anti-Clip Limiters 
work by dynamically reducing the amplifi er 
gain if the output stage is driven into clip, 
thereby reducing potentially damaging distor-
tion to moderate levels. 

While some audio systems may already con-
tain protective limiters preceeding the amplifi er 
in the system, the amplifi er’s Anti-Clip Limiters 
generally will not noticeably affect output qual-
ity. For systems without additional protection, 
the Anti-Clip Limiters can enhance your sys-
tem’s output quality and prevent catastrophic 
damage to your speakers. 

Even with the Anti-Clip Limiters, your amplifi er 
should never be operated at a level which 
causes the front-panel Clip LEDs to illuminate 
constantly. While the Anti-Clip Limiters help to 
prevent damage due to signal distortion, your 
speakers can still be damaged by excess power 
dissipation.

5.1.2 Fault
The amplifi er will light the Fault LED (Figure 
5.1) of an amplifi er channel under fi ve different 
conditions:

1. 

When the amplifi er is fi rst powered up, 
until the unit is ready for operation.

2. 

If the heatsinks reach a temperature above 
normal working limits.

3. 

If the transformer thermal protection cir-
cuit is activated.

4. 

If amplifi er output wires develop a short-
circuit.

5. 

Should the amplifi er output stage become 
non-operational.

The Fault status of the amplifi er can also be 
monitored remotely by attaching a signaling 
device to the Fault jack (see Figure 5.2). For 
suggestions for external signaling circuits to 
use, see Section 1.5 of the Crown Amplifi er 
Application Guide, available on the Crown 
website at www.crownaudio.com.

5.1.3 High-Pass Filters
Very low frequency signals contain no useful 
musical energy, waste valuable amplifi er power 
and headroom, and can be damaging to 
your speakers. Your Crown amplifi er provides 
switchable high-pass fi lters to remove these 
signals from each channel’s output. 

For each channel, a back-panel, three-position 
switch provides optional settings of Flat, 30 
Hz, 40 Hz, or 50 Hz (left to right, see Figure 
5.3). The 30 Hz setting is suitable for all 
full-range and low-frequency applications. The 
lower-frequency settings may be selected when 
the amplifi er is being used to drive a sub-bass 
program; use only with speakers that provide a 
useful frequency response below the frequency 
setting. The FLAT setting provides bypass of 
the high-pass fi lters, for use when subsonic 
protection is provided elsewhere in the system.

5.2.1 BCA
BCA (Balanced Current Amplifi er) is Crown’s 
patented, cutting-edge technology that gets 
more power out of an amplifi er with less waste 
than was ever before possible. A completely 
new adaptation of standard amplifi er design, 
Crown’s BCA “switching” amplifi er design pro-
vides for high output, exceptional reliability 
and nearly twice the effi ciency of typical ampli-
fi er designs.

Crown’s BCA “switching” technology is a com-
pletely new adaptation of standard switching 
(PWM) amplifi er design. In fact, BCA is differ-

ent enough from other amplifi er classes that 
it received a patent and merits it’s own class 
designation, “class-I.” 

BCA technology offers several key advantages. 
It provides unprecedented effi ciency, requiring 
less power from the AC supply than other 
designs, meaning signifi cant cost savings over 
the life of the amplifi er. BCA handles reactive 
speaker loads easily and gracefully, by reusing 
energy returned from the speaker rather than 
dissipating it as heat or forcing the amp into 
premature current-limiting. This ability makes 
BCA models extremely resilient—especially at 
low, 2-ohm impedances. It also makes them 
more reliable, since they are not constantly 
stressed to their limits or subjected to exces-
sive heat. Best of all, as proud owners can 
attest, amps with BCA technology sound great, 
with a powerful low-end that stands out from 
the competition.

5.2.2 Switching Power Supply with 
PFC
Crown’s new Switching Power Supply with PFC 
provides a range of benefi ts over both non-
switching and conventional switching power-
supply designs. 

Typical non-switching power supplies require 
large, heavy transformers in order to produce 
the required power at the output stage. These 
transformers must be large to absorb the sub-
stantial waste that occurs when operating 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 fi rst convert the AC 
up to a much higher frequency, thereby reduc-
ing waste. 

However, in both non-switching and conven-
tional switching designs, phase differences 
occur within the power supply due to the 
inductance of the transformer. This phase dif-
ference prevents much of the available power 
from the AC mains from making its way to the 
load.