Dolby
®
Model CP650 Installation Manual
Front-Panel and Alignment Overview
3-4
Level Display
The main fader level is displayed as a two-digit number. Starting from a display of
0.0
,
the level increases from –90 to –10 dB (display 4.0) as the fader knob is turned
clockwise. The level then increases in smaller steps from –10 to +10 dB (display 10).
As with previous generations of Dolby cinema processors, a fader setting of 7.0
(0 dB) is the nominal correct operating level. This setting matches the level used
during production of the film.
Main Fader Knob
Use this knob to adjust the sound level. A fader reading of 7.0 is the nominal correct
operating level. The main fader knob rotates continuously with no end-stops. The
knob is also used for data selection during setup operations.
When the fader knob is rotated between readings 0 and 4.0, the output level changes
in 20 dB steps between –90 and –10 dB. When the fader knob is rotated between
readings 4.0 and 10, the output level changes in 3 1/3 dB steps between –10 dB and
+10 dB.
9
-60
-50
-40
-30
-20
-10
3
2
4
5
6
7
8
-70
-80
-90
Fader Level
Output
Level (dB)
1
0
10
0
10
20 dB
per step
3 1/3 db
per step
Figure 3–3
Fader Characteristic
Projector Signal Indicators
P1
and
P2
show which projector optical input has been selected.
Bypass Power Supply Failure Indicator
This indicator lights if a problem is detected in the bypass power supply circuitry.