Input Sensitivity Adjustment; Additional Load Protection - Crown 1400 CSL Reference Manual

eration, distortion and excessive heating.

2.3 Input Sensitivity Adjustment

The input sensitivity switch inside the amplifier is set to
0.775 volts at the factory. It can be changed to 1.4 volts
or a voltage gain of 26 dB as follows:
1. Turn off and unplug the amplifier from the AC source.
2. Remove the access cover on the back panel.
3. Locate the labeled access hole for the sensitivity switch.
4. Set the switch to the desired position.
5. Replace the access cover plate.
When set to 26 dB gain, the 460 CSL requires a 2.0 volt
input, the 800 CSL requires a 2.5 volt input and the 1400
CSL requires a 3.2 volt input to deliver full output into an
8 ohm load.

2.4 Additional Load Protection

Because CSL amplifiers can generate enormous
power, it may be desirable to protect loudspeakers from
damage due to excessive power. A common way to do
this is to put a fuse in series with the load. This may be
accomplished with a single fuse to protect the entire
system, or by fusing each driver separately. Use Figure
2.4 to find the correct fuse.
Example: (A) Choose the peak music power for the loudspeaker
(such as 75 watts). (B) Find the loudspeaker impedance (8
ohms). (C) Draw a line between points A and B. The line inter-
sects the middle scale at the correct fuse value (1.5 amps).
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CSL Series Power Amplifiers
1.0
1.2
1.4
1.6
20
2
15
2.5
10
8
3
6
5
4
4
5
3
6
2
Example: Z = 8 ohms.
7
Peak Power = 75 W
1.5
8
Answer: Fuse = 1.5 A
1
9
.8
10
.6
12
.5
14
.4
16
.3
20
.2
25
.15
30
.1
.08
40
Fig. 2.4 Loudspeaker Fuse Nomograph
3000
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60
40
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8
6
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1.5
1