Dolby Laboratories CP500 User manual

Film-Tech
The information contained in this Adobe Acrobat pdf
file is provided at your own risk and good judgment.
These manuals are designed to facilitate the
exchange of information related to cinema
projection and film handling, with no warranties nor
obligations from the authors, for qualified field
service engineers.
If you are not a qualified technician, please make no
adjustments to anything you may read about in these
Adobe manual downloads.
www.film-tech.com

Model CP500
Digital Cinema Sound
Processor
Users' Manual
Issue 2 Part. No. 91372

Users' Manual
For
Model CP500
Digital Cinema Sound Processor
Dolby Laboratories Incorporated
U.S.A. 100 Potrero Avenue, San Francisco, CA 94103
Tel: [phone]; Fax: [phone]; www.dolby.com
U.K. Wootton Bassett, Wiltshire SN4 8QJ
Tel: [phone]; Fax: [phone]
WARRANTY INFORMATION - USA: Warranty on the product covered by this manual is subject to the limitations and disclaimers set forth in
the warranty disclaimer originally shipped with the product and also printed on the back of the invoice.
Digital decoding covered by the following U.S. patents: 4,790,016, 4,914,701, 4,799,260 4,941,177, 5,109,417, 5,142,656, 5,230,038,
5,274,740, 5,297,236, 5,357,594, 5,463,424, 5,583,962, 5,608,805, and other worldwide patents granted and pending.
Dolby and the double-D symbol are registered trademarks of Dolby Laboratories Licensing Corporation.
Windows is a trademark of Microsoft Corporation
©1997 Dolby Laboratories Inc. ISSUE 2
Software v 1.30
S97/11128/11508
Dolby Part No. 91372

TABLE OF CONTENTS
SECTION 1 INTRODUCTION
1.1 About the Dolby CP500.......................................................................1-1
1.2 About This Manual...............................................................................1-1
SECTION 2 OPERATING INSTRUCTIONS
2.1 The CP500 Front Panel........................................................................2-1
2.1.1 Soft Keys: SK1 to SK8......................................................... 2-1
2.1.2 Hard Keys..............................................................................2-2
Formats...............................................................................2-2
Menu...................................................................................2-2
Cancel.................................................................................2-3
OK......................................................................................2-3
Exit.....................................................................................2-3
Other Controls and Indicators ........................................................ 2-2
Fader Level Indicator .........................................................2-3
Mute ...................................................................................2-3
Bypass ................................................................................2-3
2.2 System Password..................................................................................2-4
2.3 Normal Operation................................................................................. 2-4
2.3.1 Power On...............................................................................2-4
2.3.2 Format Selection ...................................................................2-5
2.3.3 Automatic Selection of Dolby Digital Format ......................2-5
Operation With Standard Format Screen ...........................2-5
Operation with Custom Format Screen and Special
Configurations....................................................................2-7
2.3.3 Main Fader ............................................................................2-7
2.3.4 Auditorium Fader..................................................................2-7
2.3.5 Mute Function.......................................................................2-8
2.3.6 Operation With an Automation System ................................2-8
2.4 Bypass Operation .................................................................................2-8
2.4.1 Manual Bypass Selection .....................................................2-10
2.5 Customizing Features..........................................................................2-11
2.5.1 Setting the LCD Display Contrast........................................2-11
2.5.2 Setting Mute Speed ..............................................................2-12
2.5.3 Customizing the Format Display Screen..............................2-13
SECTION 3 MAINTENANCE AND ADJUSTMENTS
3.1 Soundhead Maintenance ......................................................................3-1
3.1.1 Analog Sound System...........................................................3-1
3.1.2 Dolby Level Adjustment .......................................................3-2
3.1.3 Digital Sound System............................................................3-4
Replacing the Exciter Lamp...............................................3-4
3.2 Print Cleanliness................................................................................... 3-5

ii
SECTION 4 TROUBLESHOOTING
4.1 During the Show...................................................................................4-1
4.1.1 If Film Sound Is Lost:............................................................4-1
4.1.2 If One Channel Fails or is Distorted......................................4-3
4.1.3 If Switching to Bypass Does Not Restore Sound..................4-3
4.1.4 If You Hear Extraneous Noises When Playing a Digital
Film .......................................................................................4-3
4.1.5 Excessive or Inappropriate Sound From Surround
Speakers.................................................................................4-4
4.1.6 On CP500s Equipped with Cat. No. 683 Electronic
Crossover:..............................................................................4-4
4.2 Between Shows ....................................................................................4-4
Analog Film Sound Signal Path LEDs...............................4-5
(Be certain that Format 04 is selected)...............................4-5
Digital Film Sound Signal Path LEDs................................4-6
Bypass Signal Path LEDs...................................................4-7
4.3 Troubleshooting Chart..........................................................................4-7
Appendix A How to Identify Sound Tracks on Prints
Appendix B Dolby Test and Demonstration Films
Appendix C The Evolution of Dolby Film Sound
Appendix D Fold-Out Drawings
Software Menu Tree
Circuit Card Locations

SECTION 1
INTRODUCTION
1.1 About the Dolby CP500
Dolby Laboratories has continuously established new benchmarks for motion
picture sound. The CP500 Digital Cinema Processor maintains that tradition,
setting new standards for performance, value, flexibility, and convenience. Once
installed, the Dolby CP500 Cinema Processor becomes the heart of your theater
sound system. All sound sources are connected to the CP500, which processes the
signals appropriately and feeds them to the power amplifiers. Entirely self-
contained, the CP500 provides both Dolby Digital and Dolby analog processing.
An easy-to-read LCD screen and uncomplicated front-panel "soft keys" make it
easy to operate. Software that can be readily programmed, controls any existing or
future format.
Built-in diagnostic software enables theater staff to verify performance of the
complete theater sound system. Calibration settings for a given theater can be
stored on a PC, and should the need ever arise, they can be transferred directly to
another CP500 or other modules, thereby reducing or eliminating the need for
re-calibration after repairs. As improvements to the CP500 digital control and
processing software are developed, the latest revisions can be downloaded from a
PC to the CP500 hardware. Moreover, updates to the audio coding used for Dolby
Digital soundtracks, which are included from time to time right on Dolby Digital
release prints, download automatically into the CP500 the first time such a print is
played in the cinema.
1.2 About This Manual
This Users’ Manual has been prepared specifically to help projectionists get the
most from the Model CP500 and the theater sound system once it has been
installed and aligned (installation and alignment instructions are supplied to the
local distributor or installation company). We suggest that you keep this manual
readily available.
The manual is organized as follows:
x
x
Section 2, Operating Instructions, covers the basic control functions and
operation of the CP500.
x
x
Section 3, Maintenance and Adjustments, contains tips for maintaining the
CP500 and the theater sound system.
x
x
Section 4, Troubleshooting, will help you track down problems in the sound
system without test equipment. It consists of a troubleshooting chart and
procedures to follow during a show, between shows, and after closing.
x The Appendices contain valuable background information which will help you
get the most out of the Model CP500 and your theater sound system.

1-2
For the sake of clarity, boldface type is used for all specific references to the CP500
controls and their labels, such as Mute, and front-panel Main Fader. In addition,
indicator lights on the CP500 are referred to in the text as LEDs (light-emitting
diodes).
WARNING
The CP500 was adjusted initially by a specially-trained engineer so
that your theater would have the same standard playback
characteristics as the dubbing theaters in which all Dolby films are
mixed. This results in the most accurate reproduction possible.
Never attempt to adjust any controls within the CP500 except
those specified in this manual.
All other controls are for use by a trained engineer when the CP500
is first installed or repaired. Adjusting these controls requires the
use of special test equipment. Misadjusting these controls can have
an adverse effect on the sound in your theater and will require a
service call to restore proper operation. The first thing to do when
you have a problem is to consult Section 4 Troubleshooting, and
not arbitrarily adjust these specialized controls.
In addition, do not adjust any of the controls on the other audio
equipment in your theater sound system, such as power amplifiers,
which have been preset by the installer. For example, misadjusting
the power amplifier gain controls can cause channel imbalance
and/or too much power amplifier noise. Those controls have been
set by the installer for correct channel balance and so that the
playback level in the theater is correct with the fader set to 7.0. If a
satisfactory level can only be achieved with the fader set to some
other level, the gain controls on the power amplifiers have been
misaligned and should be recalibrated by a service engineer.
To avoid the risk of electrical shock or fire, do not remove the
power supply housing located on the rear of the CP500 unit or
the rear of the Digital Soundhead.

SECTION 2
OPERATING INSTRUCTIONS
2.1 The CP500 Front Panel
2.1.1 Soft Keys: SK1 to SK8
(SK1)
(SK3)
(SK4)
(SK2)
(SK5)
(SK6)
(SK7)
(SK8)
The buttons located on each side of the LCD display are called "soft keys" (SK).
They do not have a single fixed function. Their function is software controlled and
can change based on the current screen displayed. The purpose of each key is
shown on the display screen.
2.1.2 Hard Keys
The single large and four small keys along the bottom of the display are the "hard
keys". Their functions never change and they are labeled on the panel:
FORMATS
The large key on the left, FORMATS, is used to return to the Format Selection
screen from any other menu screen. This screen is displayed during normal day-to-
day operation of the CP500. If any other screen or menu is displayed, this key
returns the display immediately to this screen.
MENU
The MENU key is used as the first step in selecting all software functions and
menus except format selection. It selects or returns the unit to the top menu, one
step down from the Format Selection screen.

2-2
(SK1)
(SK3)
(SK4)
(SK2)
(SK5)
(SK8)
(SK6)
(SK7)
BYPASS INDICATOR
Indicates continuous red when unit is in
bypass mode.
MUTE ON INDICATOR
Flashes when mute is activated.
MAIN FADER/MULTI-FUNCTION CONTROL
Controls sound level and also is used for
data selection in menu operations.
FADER LEVEL DISPLAY
Displays fader setting. Ranges from 0 to 10.
Normally set to 7.0 This display shows '- -'
when in data entry mode.
MUTE KEY
Mutes output to all channels when activated.
EXIT KEY
Used to select the previous menu.
OK KEY
Used during pop-up menu operations. Selects
option currently in pop-up window selection box.
Also stores currently displayed data.
CANCEL KEY
Used during pop-up menu operations. Cancels
pop-up menu operation and restores the
previous menu or data.
MENU KEY
Used to return to the top of the menu tree.
FORMATS KEY
Used to switch to format
selection screen.
FRONT PANEL DISPLAY
Displays format and menu
screens.
FRONT PANEL DISPLAY
SOFT KEYS 1 - 8
Used to select the function shown
next to the switch in the front panel
display.

2-3
CANCEL
Many of the screens used during set-up or diagnostics contain a "Pop-Up" screen
within the main screen. The CANCEL key is used to cancel the current pop-up
operation being performed and restore any data that was changed during the pop-up
screen operation to its original value.
OK
This key is used to accept and store the current setting in a pop-up screen.
EXIT
This key is used to signal completion of an adjustment procedure or select the
previous screen.
Other Controls and Indicators
FADER LEVEL INDICATOR
To the right of the main display is another window
showing the selected fader level. As with previous
generations of Dolby cinema processors, a fader setting of
"7.0" is the nominal correct operating level. This setting
matches the level used during the film's production. As the
main fader is turned, the numbers on the display will
move from zero to ten. The knob rotates continuously
with no end stops. The number displayed will always
indicate the current level setting.
MUTE
The MUTE key is used to fade the sound down and up
without disturbing the fader setting. A green LED, MUTE
ON, located above the fader level display will flash,
indicating that the CP500 outputs are muted. Pressing the
MUTE key again will cancel muting.
BYPASS
A BYPASS LED is located to the left of the MUTE ON LED.
As with other Dolby cinema processors, the CP500 utilizes a
separate back-up power supply which is used during
emergency operation. If the CP500 is operating in bypass
mode, this red LED will come on (not flashing). If there should
be a failure, the system can switch into bypass mode either
temporarily or permanently. A manual bypass push-button is
located inside the front panel on the right hand side of the unit.
The switch turns off the main power supply which enables the
separate bypass power supply.
Mute On
Bypass
POWER/BYPASS

2-4
2.2 System Password
Many of the CP500 alignment functions are normally protected from unauthorized
access by using a system password. A password is stored by the installation
technician after the system is aligned in order to block any changes to the B-chain
alignment, calibrated level settings, or time delays. Knowledge of this password is
required to enter these special CP500 menus.
2.3 Normal Operation
2.3.1 Power On
After initial installation, the power-up state of the unit may be selected from the
following choices. Each time the CP500 is connected to power or switched on, it
automatically sets itself to the selected "wake-up" state:
x Projector 1or 2selected by the installation technician.
x Front-panel main fader or auditorium fader (see manual section 2.3.4)
activated and set to the last fader setting before power was turned off.
x The film sound format which was active when power was removed, or
the film sound format previously stored as the "wake-up" format. (The
format options can be set using the procedure described later in this
section.)
If power has been removed for longer than approximately one week, the wake-up
state is
x Projector 1 selected. (The "wake-up" projector may have been set to
Projector 2 by your installation technician.)
x Front-panel main fader activated and set to the last fader setting before
power was turned off
x Format 01 Mono
When power is first applied, the first screen which
appears displays the revision level of the software.
Next, a brief "Loading System" message is
displayed.
In a few seconds, the Current Format screen
appears. This is the normal screen, and the only
screen you will need for ordinary purposes.
NOTE: The exact formats and their order on the
your screen may be different from the figure here if
Custom Screen has been selected.

2-5
2.3.2 Format Selection
Select the desired film soundtrack format or your non-sync source by pressing the
appropriate softkey. The LED next to the key illuminates, the text next to the
softkey is reversed (dark), and the format number appears under Current Format to
confirm that the format was selected. Common formats are as follows:
x 01 Mono: for all optical prints of any vintage with conventional mono
optical (“Academy”) soundtracks.
x 04 Dolby A-type: for Dolby releases, except those marked SR or Digital.
x 05 Dolby SR: for releases marked as having a Dolby SR (Spectral
Recording) soundtrack or for Dolby Digital prints if your CP500 is not
equipped with digital playback capability.
x 10 Dolby Digital: for Dolby Digital releases. The digital data is clearly
visible between the film perforations next to the analog sound track.
x 11 External 6ch: for selecting any six-channel external sound source.
(Your CP500 must be equipped with an optional Cat. No. 685 card.)
x 43 Dolby 70 mm split surround: for 70 mm films with 6-channel
magnetic soundtracks. (Your CP500 must be equipped with optional cards.)
x 60/61 non-sync1/2: for your intermission music tape or a CD player.
The film soundtrack format numbers used on the CP500 display (and also on
models CP45, CP65 and CP200) often appear on the film can and leader. If these
numbers are not supplied and you are not sure if a print is mono or stereo optical,
see Appendix A for a means to distinguish the various types of soundtracks.
2.3.3 Automatic Selection of Dolby Digital Format
CP500s equipped with versions 1.30 or later software are set up to sense the
presence of Dolby Digital data on the film and automatically switch to Dolby
Digital from any other film format. This section of the manual describes how to use
this feature.
Operation With Standard Format Screen
The Standard format control screen on the CP500 comes with Formats 01 (Mono),
04 (A-Type), and 05 (Dolby SR) set up so that auto-digital will occur from them.
These formats are marked by an “s” (for sources) on the screen.

2-6
Format 10 is the format that the auto-digital system will switch to when good
Dolby Digital data is detected. It is marked with an “a” (for automatic) on the
screen. Format 10 is defined as the “target” format, in this case.
To enable the auto-digital feature:
MENU
SK7
Press Menu.
Then, press SK7.
Pressing SK7 alternately enables and
disables the auto-digital feature.
To disable the auto-digital feature:
MENU
SK7
You may disable auto-digital operation
by pressing the MENU key and SK7.
Pressing SK7 alternately enables and
disables the auto-digital feature.
FORMATS Menu Cancel OK Exit
10 a
Dolby
Digital
Alternately, if the unit is currently
playing digital audio in Format 10,
select Format 05 (SK3).
A dialog box will ask you if you want to
disable auto-digital operation.
NOTE : The dialog box will not appear and auto-
digital will not be disabled unless the CP500 is
currently playing in Format 10.
x Press the OK key and it will disable
auto-digital.
x Press the CANCEL key and it will
leave the CP500 as it was.

2-7
Operation with Custom Format Screen and Special Configurations
If the installation engineer has configured your CP500 to be different from the
standard screen, the same operating methods apply. Formats designated with an “s”
are source formats for the auto-digital feature, and the format(s) designated with an
“a” is the target format(s). Disabling and enabling the feature works in the same
way as described above.
2.3.3 Main Fader
The main fader (or front panel knob) on the front panel of the CP500 controls the
volume level in the theater in both the normal and bypass operating modes. When
the CP500 has been correctly installed, setting the fader to "7.0" provides the
proper level in your theater for any Dolby encoded film. It will play at the level at
which the film was mixed.
Although a minor adjustment in playback level might be required under unusual
circumstances, you should avoid significant deviations from the correct level "7.0"
established by the installer. If the playback level is set too low, dialogue will be
hard to understand; too high a level will give rise to complaints from the audience
and under extreme circumstances can damage the theater's sound system.
2.3.4 Auditorium Fader
If an analog (not a Dolby Cat. No. 689 Digital Remote Unit) auditorium fader has
been installed, it is activated by performing the following menu steps:
FORMATS Menu Cancel OK Exit
Format
Selection
Menu
key
press:
screen shows:
Press the MENU key.
Press Auditorium Fader (SK6). Turn
the front panel knob to the Enabled
position.
FORMATS
Press the FORMATS key to return to
the format control screen. The fader
level display will show “AU”.
NOTE: When the auditorium fader is selected, the CP500 front panel main fader and any Cat. No. 734 remote
faders or Cat. No. 689 remote unit faders installed in your system will be disabled. Only the auditorium fader
will be active.

2-8
2.3.5 Mute Function
The MUTE key is useful if the film breaks or runs out, while the projector is
active, since it suppresses the very loud signal that occurs when leaders or tails
pass through the sound gate.
When you press the MUTE key, the volume will automatically fade all the way
down on all channels. A green LED, MUTE ON, located above the fader level
display will flash, indicating that the CP500 outputs are muted. When you press the
MUTE key again, or select a new format, the volume will automatically rise to the
level set by the main fader.
Use the mute function between intermission music and projector-start to prevent
the audience from hearing annoying thumps and leader crackle at the beginning of
the show.
2.3.6 Operation With an Automation System
If the CP500 in your theater is connected to automation equipment, the format keys
and their associated LEDs may be duplicated elsewhere. In most cases, the front
panel controls of the CP500 can usually be used to override commands from the
automation system; however, as automation equipment differs from installation to
installation, check with the installer of your system if you have any questions about
its operation and whether you can easily override automation commands.
2.4 Bypass Operation
The CP500 has an independent power supply for emergency operation. If the main
power supply or processor circuitry fails, the unit will automatically switch to
bypass operation, allowing the show to continue with limited sound processing
functions. Bypass operation is signaled by the red (not flashing) bypass LED
located above the main fader level display on the front panel.
In the case of other problems, such as distortion or the loss of a channel, the bypass
mode can be selected manually by means of a push-button switch located inside
the front panel on the right hand side of the unit. For more information in selecting
bypass manually, see Section 2.4.1.
There are other components in the theater sound system that could also fail. Be
sure to refer to Section 4, Troubleshooting, any time there is a problem.

2-9
The following occurs when the CP500 is in the bypass mode:
x Only the front panel main fader operates, no other remote fader will work.
x All other commands from the front panel keys are ignored by the unit.
x The optical preamp output of the selected projector remains operational and is
fed to the CP500 output card.
x Even when a stereo print is playing, a mono signal is fed to all the screen
speakers. Thus, you can switch to the bypass mode to keep the show going if
one of the power amplifiers fails.
x The Dolby digital processors, A-type noise reduction circuitry, SR processors,
2:4-channel decoder, screen speaker equalizers, surround equalizers, and
subwoofer circuits are out of the signal path.
If the unit has entered bypass mode automatically due to a failure in the main
power supply or the main power source, then the front panel LEDs will be off
except the bypass LED.
If the unit has entered bypass mode automatically due to a failure in the main signal
path, then the front panel LEDs may still be on. A message on the front panel
screen will indicate the nature of the failure.
Be sure to follow the troubleshooting procedures and if necessary, call your trained
service engineer as soon as possible.
NOTE: The CP500 will not operate -- even in the bypass mode -- if there is a fault in any of the
following areas:
x
The AC mains power to the bypass transformer or main power supply
x
The Cat. No. 661 optical preamplifier card
x
The bypass circuitry section of the Cat. No. 682 card
x
The Cat. No. 683 (optional) crossover card for bi-amplified installations
x
The bypass power transformer itself
It is strongly recommended that spares of the above cards and the transformer be kept on hand for
substitution in emergencies.
If the theater is equipped with film platters and the unused projector input on the rear of the CP500
is accessible, the projector solar cell connector can be moved from Optical 1 to Optical 2 in order to
try using the second optical preamp circuit. However, this input may not be set up correctly, so care
will be needed with the volume control.

2-10
2.4.1 Manual Bypass Selection
The CP500 can be manually switched to bypass using either of two methods:
1. Open the front panel and operate the pushbutton
switch located on the right-hand side of the unit.
Use this method in an emergency situation, or
2. Perform the following steps:
MENU
SK1
Press the MENU key.
Press System Setup (SK1).
CANCEL
Press Bypass (SK8).
A pop-up box appears, warning that the
CP500 is now set to bypass operation.
Press the CANCEL key to return the
CP500 to normal operation.
POWER/BYPASS

2-11
2.5 Customizing Features
2.5.1 Setting the LCD Display Contrast
The Contrast level of the front panel LCD display can be adjusted by following
these menu steps:
CP500 Controls
key
System Setup
key
Format
Selection
Menu
key
FORMATS Menu Cancel OK Exit
screen shows:
press:
Menu
Selection
System
Setup
screen shows:
screen shows: press:
press:
Begin the procedure by pressing the
MENU key,
Press System Setup (SK1),
Press CP500 Controls (SK1).
FORMATS Menu Cancel OK Exit
OK
Press LCD Contrast (SK1).
A pop-up box appears.
Set the desired appearance by rotating
the front panel knob to adjust the
display contrast.
Then press the OK key to save the
contrast setting.

2-12
2.5.2 Setting Mute Speed
The length of time it takes for the sound to fade from normal setting to muted
(when the MUTE key is pressed) is adjustable. To make this adjustment,
CP500 Controls
key
System Setup
key
Format
Selection
Menu
key
FORMATS Menu Cancel OK Exit
screen shows:
press:
Menu
Selection
System
Setup
screen shows:
screen shows: press:
press:
Press the MENU key,
System Setup (SK1),
CP500 Controls (SK1),
Mute Speed Adjustment (SK7).
Use the main fader to select the fade-out
time you prefer. The time displayed is
the approximate time to silence. You
can test the mute function while in this
window to see whether you are satisfied
with the setting chosen.
OK
Press OK when you are satisfied with
the setting or press CANCEL if you
wish to retain the original setting.
FORMATS
Press FORMATS to return to the
normal format control screen.
NOTE: When the Mute function is being executed, any other control actions will be delayed for
approximately 1.2 times the selected mute time.

2-13
2.5.3 Customizing the Format Display Screen
There are two types of Format Selection display screens. The unit is shipped in
Standard Mode, which allows selection of eight commonly used formats. There
also exists a Custom Mode which allows the user to program the softkeys to show
formats of his own choosing, along with changes to the fader setting and projector
selection for each of these softkeys.
Format
Configuration
key
System Setup
key
Format
Selection
Menu
key
FORMATS Menu Cancel OK Exit
screen shows:
press:
Menu
Selection
System
Setup
screen shows:
screen shows: press:
press:
Begin the procedure by pressing the
MENU key.
Press System Setup (SK1).
Press Format Configuration (SK3).
Switching the format screen display
between Standard and Custom is next.
FORMATS Menu Cancel OK Exit
OK
FORMATS Menu Cancel OK Exit
Press Format Screen (SK2).
A pop-up box appears.
Rotating the front panel knob selects
between Standard and Custom modes.
Select Custom.
Then press the OK key to complete the
action.
To program the softkeys, choose Build
Format Selector (SK3).