Crown d-45 Guia Do Utilizador

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.

Your amplifier is protected against all common 
hazards that plague high-power amplifiers, 
including shorted, open or mismatched loads; 
overloaded power supplies, chain destruction 
phenomena, input overload and high-frequency 
blowups.

Protection against shorted and mismatched 
loads is provided by an instantaneous limiter 
that automatically limits current to the maxi-
mum safe value for the output transistors. With 
a loudspeaker, you can tell the amplifier has 
activated load protection because it causes 
audible distortion. The noise might be com-
pared to crossover notch distortion or a snap-
ping sound, depending on the load 
characteristics. Loudspeaker systems with 
impedances of 4 ohms or higher should not 
activate the protection system.

All voltage amplification circuitry is designed to 
limit current. So in the extremely unlikely event 
of a device failure, the amplifier will prevent fur-
ther damage. The input stages are protected 
from overload damage by series resistors. The 
unit also features a controlled slew rate and a 
V-I limiter that protect the amplifier from high-
frequency (RF) blowups.

Your amplifier is factory-set for dual (stereo) 
operation. As an option, you may have the unit 
configured for higher-power, single-channel, 
bridge-mono operation. If you want the bridge-
mono modification, take the unit to an autho-
rized Crown Service Center.

IMPORTANT: Critical differences 
between dual and mono wiring are 
described in Section 2.6.2. 

The input sensitivity of your amplifier is fac-
tory-set to 26 dB gain. As an option, the unit 
can be set to an input sensitivity of 0.775 volt 
by an authorized Crown Service center.

For most applications, the amplifier’s default 
setting of 26 dB gain will be ideal. With this 
default setting, full output power is achieved 
with an input signal of 0.632 volts for the D-45, 
and 0.837 volts for the D-75A.

Some applications may require the gain struc-
ture to be calculated based on a sensitivity of 
0.775 volts. And although the 26 dB gain set-
ting provides a sensitivity for each amplifier 
that is very near 0.775 volts, the 0.775-volt 
sensitivity setting is provided for applications 
that demand this sensitivity with a high level of 
precision.

A Crown Service Center can activate the 0.775 
volt input sensitivity without voiding the war-
ranty.