XLS Series Power Amplifiers
5 Advanced Features and Options
Figure 5.1 Anti-
Clip Limiter switch
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.
5.1 Protection Systems
Your Crown amplifi er provides extensive pro- tection and diagnostic capabilities, including
filters, 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
While some audio systems may already con- tain protective limiters preceeding the amplifi er in the system, additional use of the
Regardless of whether or not the
The
5.1.2 High-Pass Filters
Figure 5.2 High- Pass Filter switch
Figure 5.3 Fault indicator
your speakers. Your Crown amplifi er provides switchable
For each channel, a
5.1.3Output Current Limiting
Output Current Limiting circuitry protects the amplifi er output stage from damage caused by short circuit loads.
5.1.4DC 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
230V 120V
XLS202 T6.3A T6.3A
XLS402 T6.3A T10A
Figure 5.4 Ampli- fier fuse rating
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 fire 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.
Very low frequency signals contain no useful | XLS602 | T6.3A | T10A |
musical energy, waste valuable amplifi er power and headroom, and can be damaging to
Operation Manual | page 11 |