Crown XLS 602 Manual De Usuario

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.

5.1 Protection Systems
Your Crown amplifi er provides extensive pro-
tection and diagnostic capabilities, including 
built-in anti-clip limiters, switchable high-pass 
fi lters, output current limiting, DC protection, 
fuses, and special thermal protection for the 
unit’s transformers.

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, additional use of the Anti-Clip 
Limiters generally will not noticably affect 
output quality. For systems without additional 
protection, use of the Anti-Clip Limiters can 
enhance your system’s output quality and pre-
vent catastrophic damage to your speakers. 

Regardless of whether or not the Anti-Clip Lim-
iters are enabled, 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.

The Anti-Clip limiters are enabled by moving 
the rear-panel Limiter switch to the “IN” posi-
tion (see Figure 5.1). 

5.1.2 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 30 Hz 
(left), 15 Hz (center), or OFF (right) (see Figure 
5.2). The 30 Hz setting is suitable for all full-
range and low-frequency applications. The 15 
Hz setting 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 30 Hz. The OFF set-
ting provides bypass of the high-pass fi lters, 
for use when subsonic protection is provided 
elsewhere in the system.

5.1.3 Output Current Limiting
Output Current Limiting circuitry protects the 
amplifi er output stage from damage caused by 
short circuit loads.

5.1.4 DC Protection
DC Protection disconnects the loudspeaker 
load in the event of an output DC offset exceed-
ing 2V. In such an event the yellow Fault LED 
will illuminate (see Figure 5.3) and both amplifi er 
channels will be muted. In the majority of cases, 
DC protection is indicative of a faulty amplifi er 
channel, and will be accompanied by an illumi-
nated Clip LED, even with no input connected 
and level controls set at minimum. If this is the 
case, contact your dealer or service center.

5.1.5 Fuse
The high-voltage power supplies of your 
Crown amplifi er are protected by a fuse. The 
fuse rating varies depending on model and 
supply voltage as follows.

 

XLS202 T6.3A T6.3A

XLS402 T6.3A  T10A

XLS602 T6.3A  T10A

The fuse rating for your amplifi er will also 
be indicated on the amplifi er back panel label 
below the power connector (see Figure 5.4).

Crown amplifi ers do not blow their fuses 
unless something is wrong. Repeated fuse 
failure typically indicates problems with the 
amplifi er or installation which should be cor-
rected immediately. 

Should the fuse need to be replaced, take care 
to follow these precautions:

1.  Remove power before replacing.

2.  Never replace the fuse with a higher rating 

than specifi ed; this could result in a 
fi re hazard.

3.  IMPORTANT: The orientation of the fuse 

drawer determines the operating voltage of 
your amplifi er. Should the fuse need to 
be replaced, take care to replace the fuse 
drawer so that the voltage numbers dis-
played on the top, left corner of the drawer 
are correct for your local supply. 

5.1.6 Thermal  Protection
The Thermal Protection circuit will activate 
should the internal heatsink temperature 
exceed proper operating temperatures (194 
degrees F, 90 degrees C). When the heatsink 
temperature has fallen to a safe level, this 
protection circuit will automatically be reset. 
Principle causes of thermal protection are: 1) 
Inadequate ventilation of the equipment rack; 
2) Incorrect load impedance; 3) Output cable 
short circuit; 4) Blocked air vent; 5) Heatsinks 
in need of cleaning; 6) Cooling fan failure.

The cause of your amplifi er’s thermal protection 
state should be determined and corrected as 
soon as possible. Without correction, the Ther-
mal Protection circuit will typically reactivate.