Dolby Laboratories DA20 Installation Manual
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Dolby Laboratories DA20 Installation Manual

Dolby Laboratories DA20 Installation Manual

Digital film sound processor
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MODEL DA20
DIGITAL FILM
SOUND PROCESSOR
Installation Manual
ISSUE 6
Part No. 91341

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  • Page 1 MODEL DA20 DIGITAL FILM SOUND PROCESSOR Installation Manual ISSUE 6 Part No. 91341...
  • Page 2 5,297,236, 5,357,594, 5,463,424, 5,583,962, 5,608,805, and other worldwide patents granted and pending. All requests for repairs or information should include the unit serial number to assure rapid service. Dolby and the double-D symbol are registered trademarks of Dolby Laboratories. ©1997 Dolby Laboratories Inc.

  • Page 3: Table Of Contents

    Making a Custom Video Cable ....................2-5 Connection to Motor Start Relays–For 2 Projector Installations .......... 2-9 Connection to Dolby Cinema Processors ................2-10 2.5.1 Installation of DA20 with CP55 ................2-10 2.5.2 Installation of DA20 with CP65 ................2-40 2.5.3 Installation of DA20 with CP200 ................
  • Page 4 SECTION 7 MAINTENANCE AND ADJUSTMENTS Digital Soundhead Maintenance ....................7-1 Print Cleanliness ......................... 7-2 Adjustments ..........................7-2 SECTION 8 UNIT SERVICING / IN CASE OF DIFFICULTY Troubleshooting During the Show ................... 8-1 Problem Identification ........................ 8-2 Determining Software Revision No..................8-5 Starting and Program Loading ....................

  • Page 5: Specifications

    Maximum 100 Watts; typical 60 Indicates that the system has ±0.5 dB. Watts. selected Dolby Stereo SR (analog) operation. Noise Level More than 72 dB CCIR/ARM Motor 1/ Motor 2 below Dolby level at DA20 Indicates “motor running” signals outputs. used for changeover.

  • Page 6: About This Manual

    This manual contains essential information on the installation and alignment of the Dolby Model DA20 Digital Film Sound Processor. It is designed to operate with one of Dolby Laboratories’ model CP500, CP200, CP65, CP55, or CP45 Cinema Processors to allow decoding and correct playback of the Dolby Digital optical soundtrack format.
  • Page 7 The system alignment procedure is divided into two parts: The mechanical alignment of the Cat. No. 700 Digital Soundhead. The electronic adjustment of the DA20 electronics chassis. UTION This Installation Manual is for use by qualified personnel only. To avoid electric shock do not perform...

  • Page 8: Section 1 Equipment Required/Power Requirements

    The Dolby Model DA20 may be operated from any nominal 120Vac or 240Vac power source. Voltage selection is automatic within the DA20. The switching power supply used in the DA20 may be used with mains voltages in the range 85-265 Vac, 50-60 Hz without adjustment for input voltage.
  • Page 9 Regulatory Notices This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment.
  • Page 10 IEC NOTICES IMPORTANT SAFETY NOTICE This unit complies with the safety standard IEC65. To ensure safe operation and to guard against potential shock hazard or risk of fire, the following must be observed: • If the unit has a voltage selector, ensure that it is set to the correct mains voltage for your supply. If there is no voltage selector, ensure that your supply is in the correct range for the input requirement of the unit.

  • Page 11: Section 2 Initial Setup And Installation

    DP75, FP20, FP30 Order Cat. No.696 Adapter Kit (plate Part No. 67139) Additional plates may become available. Consult Dolby Laboratories for availability. Mounting the soundhead on a projector is accomplished by selecting the appropriate adapter plates (if needed), attaching the plates to the soundhead casting, then bolting the plate to the projector and the reel arm or platter guide roller assembly.
  • Page 12 Digital Soundhead and the picture gates in the two projectors are identical. The soundhead delay setting in the DA20 is adjusted for correct synchronization of sound and picture during installation. Since only one adjustment is provided, both projectors must have the same film path length from the Digital Soundhead to the picture gate.
  • Page 13 Digital Print Threading Path Bypass Threading Path 9. Route appropriate conduit from the audio rack where the DA20 is to be installed to the Cat. No.700 Digital Soundhead, terminating the conduit at the end of the Digital Soundhead. The soundhead has an unthreaded 27 mm diameter hole in a 2 mm plate to accept 3/4"...

  • Page 14: Electrical Connections To The Digital Soundhead

    EMI emission standards. The male DB25 connector is attached to the DA20 end of the cable; on the other end a 12-way Molex connector is attached. The standard cable is 10m (about 30 feet) long. 30m (about 100 feet) or 15m (about 50 feet)

  • Page 15: Making A Custom Video Cable

    If the cable is installed in conduit then place the blocks at the DA20 end. If the cable is not in conduit then installation of these ferrite blocks is essential to prevent excessive RF energy radiation, and should be placed near each end of the cable.
  • Page 16 Wiring to the Molex Connector 1. Strip back vinyl outer jacket of cable to 3.0 inches. 2. Add 1/2 inch dia heat-shrink about 1/4 inch long near end of vinyl outer jacket. 3. Fold outer shield braid back over vinyl outer jacket. About 3 inches.
  • Page 17 7. Cut exposed wiring and twisted shield to the lengths indicated below; measured from end of the outer cable casing. white - cut to 2.8 inches 8. Strip insulated wires back .12 inch and tin 9. Install 1/16 inch dia clear shrink tubing over each drain wire of the twisted pairs and heat shrink.
  • Page 18 The pins must be inserted in the Molex connector block as shown in the following table. Perform this operation before plugging the male DB25 connector into the DA20. Incorrect placement of pins will result in damage to the Cat. No.634 CCD board or the Cat.

  • Page 19: Connection To Motor Start Relays-For 2 Projector Installations

    DA20 will not switch to analog if the digital signal is unreadable. Installation of a relay is preferred, but installing a wire link from J9 pin 1 to J9 pin 5 will cause the DA20 to assume that the motor is running constantly, allowing automatic switching to analog if required.

  • Page 20: Connection To Dolby Cinema Processors

    CP55. Unfortunately, this method makes use of the AUX format, which will be needed for use by the DA20. Therefore, if your theater is equipped with an SRA5 installed in the original way, you will need to revise the installation before proceeding further.
  • Page 21 2-11 Installation The changes below move format 05 (Dolby Stereo SR) to the format 03 button, freeing up the aux button for the Dolby Digital input. 1. Set the SRA5 CP selector switch to the “55” position. 2. Set the SRA5 Mode switch located behind the front access panel to “Remote.” 3.
  • Page 22 2-12 LEFT CHANNEL GROUND RIGHT CHANNEL Figure No. 2.6 Backplane connections at J14 4. Since the function of the front panel 03 button is now changed to format 05 and the aux button now selects Dolby Digital, an adhesive label is included to re-label the front panel.
  • Page 23 2-13 c. If an SRA5 is currently installed using the AUX format, remove diodes D61, D64, D65, D66, and D72 shown in Figure 2.7 with an . Add diode D67 shown with a d. Reinstall the Cat.No.243 in the CP55. CONTROL FUNCTIONS REMOVE D29 &...
  • Page 24 The two inputs from the DA20 (Rs and SW) will have to be soldered directly to the indicated backplane pins of the Cat. No.441. As the cable plugs in to the DA20 end of things, it will still be possible to disconnect the units from each other without soldering.
  • Page 25 2-15 remote fader indicator CAT.NO. from non from mag from aux sync mute CAT.NO. CAT.NO. CUT TRACE HERE 105K bypass indicator to power amps Rs OUTPUT Figure 2.8 CP55 Backplane Modifications for Cat. No.441 2.5.1.3 Cat. No. 441 Control Functions Label The controls on the Cat.
  • Page 26 DA20. Valid format assertions are detected when any one CTRL line is low for greater than 80ms. See the DA20 Users’ Manual for specific information related to the DA20 modes of operation and the Auto Digital feature.
  • Page 27 2-19 2.4.1.4 Cat. No. 441 Alignment The Cat. No. 441 alignment procedure (taken from the CP65 Installation Manual) begins here. Subwoofer Alignment Cat. No. Cat. No. Remove the Cat. No. 150 Card. Note that when the Cat. No. 150 card is removed, two card edge connectors are exposed on the backplane and that another slot to the immediate left of the Cat.
  • Page 28 2-20 Cat. No. 441 Alignment Instructions from the CP65 Manual Cat. No. 441—Subwoofer Alignment Step Indication Action CAT. NO. 441 auto subwoofer local active select mute local/remote Dolby Stereo Digital...
  • Page 29 2-21 Cat. No. 441 Alignment Instructions from the CP65 Manual Cat. No. 441—Subwoofer Alignment Notes The Subwoofer auto/off switch on the Cat. No. 441 card enables the subwoofer in formats other than Non-sync (format 60) , Mono (format 01) and magentic no NR (format 22).
  • Page 30 2-22 Cat. No. 441 Alignment Instructions from the CP65 Manual Cat. No. 441—Subwoofer Alignment Step Indication Action Cat. No. 90 dBC 85 dBC signal present auto freq opt gain n-sync surr mag/dig gain gain treble freq bass treble mid freq bass gain signal...
  • Page 31 2-23 Cat. No. 441 Alignment Instructions from the CP65 Manual Cat. No. 441—Subwoofer Alignment Notes Adjust the mag/dig gain control on the Cat. No. 441 card for a 90 dBC SPL (sound pressure level) in the theatre. (If this level cannot be obtained it may be necessary to change the J2 jumper setting to increase or decrease the output.) When you have obtained this level turn the mag/dig gain control down for an 85 dBC SPL.
  • Page 32 2-24 Cat. No. 441 Alignment Instructions from the CP65 Manual Cat. No. 441—Subwoofer Alignment Step Indication Action Cat. No. signal present auto freq opt gain n-sync surr mag/dig gain gain treble freq bass treble mid freq bass gain signal present Cat.
  • Page 33 2-25 Cat. No. 441 Alignment Instructions from the CP65 Manual Cat. No. 441—Subwoofer Alignment Notes Turn the freq control on the Cat. No. 441 card. A dip in the frequency response will move along the frequency axis of the RTA display. Adjust the freq control so the center of the dip is in the same band as the highest peak in the unequalized subwoofer frequency response you were asked to take note of in Step 5.
  • Page 34 2-26 Cat. No. 441 Alignment Instructions from the CP65 Manual Cat. No. 441—Subwoofer Alignment Step Indication Action REPEAT Dolby Stereo 1 12 A-type CAT. NO. 441 auto NOTE THIS LEVEL subwoofer CENTER CHANNEL –5 –10 3.15 12.5 CAT. NO. 441 auto subwoofer...
  • Page 35 2-27 Cat. No. 441 Alignment Instructions from the CP65 Manual Cat. No. 441—Subwoofer Alignment Notes If using a single microphone, relocate the microphone to at least one other location in the theatre and check the audio spectrum on the RTA. Repeat the freq, cut, and Q adjustments to obtain a good average overall equalization at these locations of the microphone.
  • Page 36 2-28 Cat. No. 441 Alignment Instructions from the CP65 Manual Cat. No. 441—Subwoofer Alignment Step Indication Action Cat. No. signal present auto freq 1 12 SAME AS opt gain n-sync surr mag/dig gain gain treble freq –5 –5 bass –10 –10 12.5 12.5...
  • Page 37 2-29 Cat. No. 441 Alignment Instructions from the CP65 Manual Cat. No. 441—Subwoofer Alignment Notes Adjust the optical gain control on the Cat. No. 441 card so that the average level of the bands from the subwoofer is at the same level on the analyzer screen as you noted for the center channel in the previous step.
  • Page 38 2-30 Cat. No. 441 Alignment Instructions from the CP65 Manual Cat. No. 441—Surround Equalization Alignment Step Indication Action RIGHT SURROUND POWER AMP Dolby Stereo A-type Cat. No. MONO SURROUND STEREO SURROUND 88 dBC 85 dBC mono eq mono gain non-sync signal present test...
  • Page 39 2-31 Cat. No. 441 Alignment Instructions from the CP65 Manual Cat. No. 441—Surround Equalization Alignment Notes The surround equalizer on the Cat. No. 441 card consists of: • A parametric mid-band section with variable cut, bandwidth, and center frequency. • Shelving type Bass and Treble controls. All connections established in the previous procedure still apply to the surround equalization alignment.
  • Page 40 2-32 Cat. No. 441 Alignment Instructions from the CP65 Manual Cat. No. 441—Surround Equalization Alignment Step Indication Action Cat. No. signal present auto freq opt gain n-sync surr mag/dig gain gain treble freq bass –5 treble –10 mid freq 3.15 12.5 bass gain...
  • Page 41 2-33 Cat. No. 441 Alignment Instructions from the CP65 Manual Cat. No. 441—Surround Equalization Alignment Notes Adjust the Left Surround bass control on the Cat. No. 441 card for as flat as possible low frequency response on the RTA. Use caution when adjusting the bass control; many surround loudspeaker systems are deficient in their low frequency response.
  • Page 42 2-34 Cat. No. 441 Alignment Instructions from the CP65 Manual Cat. No. 441—Surround Equalization Alignment Step Indication Action Cat. No. signal present D I P auto freq opt gain n-sync surr mag/dig gain gain treble freq bass –5 treble mid freq –10 12.5 3.15...
  • Page 43 2-35 Cat. No. 441 Alignment Instructions from the CP65 Manual Cat. No. 441—Surround Equalization Alignment Notes Turn the freq control so that the notch is located over the peak noted in the previous step. Adjust the Cut and Q controls for the flattest response in this part of the spectrum. Adjust the treble control on the Cat.
  • Page 44 2-36 Cat. No. 441 Alignment Instructions from the CP65 Manual Cat. No. 441—Surround Equalization Alignment Step Indication Action MONO SURROUND STEREO SURROUND 88 dBC 85 dBC Cat. No. mono eq mono gain non-sync signal present test points gain RIGHT SURROUND AMP 1 12 LEFT SURROUND AMP 1 13...
  • Page 45 2-37 Cat. No. 441 Alignment Instructions from the CP65 Manual Cat. No. 441—Surround Equalization Alignment Notes Adjust the Ls (Left surround) gain control on the Cat. No. 242 B-Chain card for a sound pressure level of 85 dBC (or 88 dBC if only one surround output is to be used). If the surround speakers are wired for stereo operation or both surround outputs are in use, switch on ( or reconnect the input to) the right surround amplifier or amplifiers.
  • Page 46 2-38 Cat. No. 441 Alignment Instructions from the CP65 Manual Cat. No. 441—Surround Equalization Alignment Step Indication Action NORMAL BYPASS bypass (switch behind panel) Cat. No. Cat. No. NORMAL BYPASS Dolby Stereo Digital...
  • Page 47 2-39 Cat. No. 441 Alignment Instructions from the CP65 Manual Cat. No. 441—Surround Equalization Alignment Notes Open the CP65 and place the NORMAL/BYPASS switch in the BYPASS position. Remove the Cat. No. 85C card and re-install the Cat. No. 150 card. Restore the BYPASS/NORMAL switch to the NORMAL position.

  • Page 48: Installation Of Da20 With Cp65

    CP65 kit. The ribbon cable with D-connectors on each end connects from J6 on the DA20 to J18 on the CP65. The round cable plugs into J8 on the DA20 and the fanning strip on the other end connects to TB4 as shown.
  • Page 49 DA20. Valid format assertions are detected when any one CTRL line is low for greater than 80ms. See the DA20 Users’ Manual for specific information related to the DA20 modes of operation and the Auto Digital feature.

  • Page 50: Installation Of Da20 With Cp200

    These connections are shown in Figure 2.11. In order for the auto digital feature to operate, the DA20 must be equipped with a Cat. No.611A card. The DA20 also needs the ability to assert each of the four CP200 format selections to determine which format selector is assigned format 10 and when detected, assert format 10 when appropriate.
  • Page 51 2-45 2.5.3.1 Cat. Nos. 517, 137L, and 560 Installation and Operation Instructions (CP200) The Cat. Nos. 517 and 560 are designed to replace the Cat. Nos. 117 and 160, respectively. Their primary purpose is to upgrade the CP200 cinema processor to handle the wider dynamic range, lower distortion signals now available from Dolby Digital.
  • Page 52 P (Left surround) and Q (Right surround) channels as appropriate. (However, where this is not practical, in the DA20 a mono surround output created by summing the left and right surround signals is provided and is routed to the S output channel in the CP200.)
  • Page 53 2-47 Cat. No. 560 settings The Cat. No.560 has six programming jumpers and one switch on it: • J1 selects high or low output level range for the CP50 Right surround output. • J2 selects high or low output level range for the subwoofer channel. •...
  • Page 54 (Cat. No. 517) SK30 pin M SK28 pin M Dolby Digital valid logic signal from (Cat. No. 517) DA20 (low = valid) SK28 pin M SK13 pin B21 Dolby Digital valid logic signal from (Cat. No. 560) DA20 (low = valid)
  • Page 55 2-49 (12) JM 4 SK18 SK 15 SK 14 SK 13 CAT.141 CAT.150 CAT.160 JM 10 JM11 JM 9 JM21 JM 22 JM 24 JM20 SK30 SK29 SK28 CAT.117 CAT.137 CAT.117 JM23 PJ24 PJ23 PJ22 PJ21 BS24 Figure 2.14 CP200 Backplane Wiring (no accessory unit)
  • Page 56 2-50 When the backplane wiring is done as shown in the figure, the operation of the Cat. No.517s for the S, P (left surround), and Q (right surround) channels is as follows: The optical surround trim (the upper pot on the left-hand Cat. No.517) now functions as a surround trim governing all three surround outputs at once when an analog optical format with surround (formats 04 or 05) is selected.
  • Page 57 2-51 No text on this page.
  • Page 58 2-52 Surround EQ Alignment Instructions from the CP65 Manual Cat. No. 441—Surround Equalization Alignment Step Indication Action RIGHT SURROUND POWER AMP Dolby Stereo A-type MONO SURROUND STEREO SURROUND 88 dBC 85 dBC...
  • Page 59 2-53 Surround EQ Alignment Instructions from the CP65 Manual Cat. No. 441—Surround Equalization Alignment Notes The surround equalizer on the Cat. No. 441 card consists of: • A parametric mid-band section with variable cut, bandwidth, and center frequency. • Shelving type Bass and Treble controls. All connections established in the previous procedure still apply to the surround equalization alignment.
  • Page 60 2-54 Surround EQ Alignment Instructions from the CP65 Manual Cat. No. 441—Surround Equalization Alignment Step Indication Action Cat. No. signal present auto freq opt gain n-sync surr mag/dig gain gain treble freq –5 bass treble –10 12.5 3.15 mid freq bass gain signal...
  • Page 61 2-55 Surround EQ Alignment Instructions from the CP65 Manual Cat. No. 441—Surround Equalization Alignment Notes Adjust the Left Surround bass control on the Cat. No. 441 card for as flat as possible low frequency response on the RTA. Use caution when adjusting the bass control; many surround loudspeaker systems are deficient in their low frequency response.
  • Page 62 2-56 Surround EQ Alignment Instructions from the CP65 Manual Cat. No. 441—Surround Equalization Alignment Step Indication Action Cat. No. signal present D I P auto freq opt gain n-sync surr mag/dig gain gain treble freq bass –5 treble mid freq –10 12.5 3.15...
  • Page 63 2-57 Surround EQ Alignment Instructions from the CP65 Manual Cat. No. 441—Surround Equalization Alignment Notes Turn the freq control so that the notch is located over the peak noted in the previous step. Adjust the Cut and Q controls for the flattest response in this part of the spectrum. Adjust the treble control on the Cat.
  • Page 64 2-58 Surround EQ Alignment Instructions from the CP65 Manual Cat. No. 441—Surround Equalization Alignment Step Indication Action MONO SURROUND STEREO SURROUND 88 dBC 85 dBC RIGHT SURROUND AMP 1 12 LEFT SURROUND AMP 1 13 Cat. No. 85 dBC signal present auto freq opt gain...
  • Page 65 2-59 Surround EQ Alignment Instructions from the CP65 Manual Cat. No. 441—Surround Equalization Alignment Notes Adjust the Ls (Left surround) gain control on the Cat. No. 242 B-Chain card for a sound pressure level of 85 dBC (or 88 dBC if only one surround output is to be used). If the surround speakers are wired for stereo operation or both surround outputs are in use, switch on ( or reconnect the input to) the right surround amplifier or amplifiers.
  • Page 66 2-60 Surround EQ Alignment Instructions from the CP65 Manual Cat. No. 441—Surround Equalization Alignment Step Indication Action NORMAL BYPASS bypass (switch behind panel) Cat. No. Cat. No. NORMAL BYPASS Dolby Stereo Digital...
  • Page 67 2-61 Surround EQ Alignment Instructions from the CP65 Manual Cat. No. 441—Surround Equalization Alignment Notes Open the CP65 and place the NORMAL/BYPASS switch in the BYPASS position. Remove the Cat. No. 85C card and re-install the Cat. No. 150 card. Restore the BYPASS/NORMAL switch to the NORMAL position.
  • Page 68 (Cat. No. 517) SK30 pin M SK28 pin M Dolby Digital valid logic signal from (Cat. No. 517) DA20 (low = valid) SK28 pin M SK13 pin B21 Dolby Digital valid logic signal from (Cat. No. 560) DA20 (low = valid)
  • Page 69 2-63 (12) SK18 SK15 SK14 SK13 CAT.141 CAT.150 CAT.160 JM10 JM11 JM21 JM22 JM24 JM20 SK30 SK29 SK28 CAT.117 CAT.137 CAT.117 JM23 PJ24 PJ23 PJ22 PJ21 BS24 Figure 2.15 CP200 Wiring with accessory unit and EQ for P, Q Channels...
  • Page 70 2-64 When the backplane wiring is done as shown in the figure, the operation of the Cat. No.517s for the S, P (left surround), and Q (right surround) channels is as follows: The optical surround trim (the upper pot on the left-hand Cat. No.517) now functions as a surround trim governing all three surround outputs at once when an analog optical format with surround (formats 04 or 05) is selected.
  • Page 71 2-65 No text on this page.
  • Page 72 2-66 Cat. No. 441—Subwoofer Alignment from the CP65 Manual Step Indication Action CAT. NO. 441 auto subwoofer local active select mute local/remote Dolby Stereo Digital...
  • Page 73 2-67 Cat. No. 441—Subwoofer Alignment from the CP65 Manual Notes The Subwoofer auto/off switch on the Cat. No. 441 card enables the subwoofer in formats other than Non-sync (format 60) , Mono (format 01) and magentic no NR (format 22). The switch must be in the auto (up) position at any time the subwoofer system is to function.
  • Page 74 2-68 Cat. No. 441—Subwoofer Alignment from the CP65 Manual Step Indication Action Cat. No. 90 dBC 85 dBC signal present auto freq opt gain n-sync surr mag/dig gain gain treble freq bass treble mid freq bass gain signal present Cat. No. signal present auto freq...
  • Page 75 2-69 Cat. No. 441—Subwoofer Alignment from the CP65 Manual Notes Adjust the mag/dig gain control on the Cat. No. 441 card for a 90 dBC SPL (sound pressure level) in the theatre. (If this level cannot be obtained it may be necessary to change the J2 jumper setting to increase or decrease the output.) When you have obtained this level turn the mag/dig gain control down for an 85 dBC SPL.
  • Page 76 2-70 Cat. No. 441—Subwoofer Alignment from the CP65 Manual Step Indication Action Cat. No. signal present auto freq opt gain n-sync surr mag/dig gain gain treble freq bass treble mid freq bass gain signal present Cat. No. signal present D I P auto freq opt gain n-sync...
  • Page 77 2-71 Cat. No. 441—Subwoofer Alignment from the CP65 Manual Notes Turn the freq control on the Cat. No. 441 card. A dip in the frequency response will move along the frequency axis of the RTA display. Adjust the freq control so the center of the dip is in the same band as the highest peak in the unequalized subwoofer frequency response you were asked to take note of in Step 5.
  • Page 78 2-72 Cat. No. 441—Subwoofer Alignment from the CP65 Manual Step Indication Action REPEAT Dolby Stereo 1 12 A-type CAT. NO. 441 NOTE THIS LEVEL auto subwoofer CENTER CHANNEL –5 –10 3.15 12.5 CAT. NO. 441 auto subwoofer...
  • Page 79 2-73 Cat. No. 441—Subwoofer Alignment from the CP65 Manual Notes If using a single microphone, relocate the microphone to at least one other location in the theatre and check the audio spectrum on the RTA. Repeat the freq, cut, and Q adjustments to obtain a good average overall equalization at these locations of the microphone.
  • Page 80 2-74 Cat. No. 441—Subwoofer Alignment from the CP65 Manual Step Indication Action Cat. No. signal present auto freq 1 12 SAME AS opt gain n-sync surr mag/dig gain gain treble –5 –5 freq bass –10 –10 3.15 3.15 12.5 12.5 treble mid freq bass...
  • Page 81 2-75 Cat. No. 441—Subwoofer Alignment from the CP65 Manual Notes Adjust the optical gain control on the Cat. No. 441 card so that the average level of the bands from the subwoofer is at the same level on the analyzer screen as you noted for the center channel in the previous step.
  • Page 82 2-76 2.5.3.5 Output level adjustments of Cat. Nos. 517 and 560 in CP200 Adjustment of P and Q channels. Select format 40 (70 mm mag no NR). Note: If only the S (mono surround output) is used proceed to step 2. Remove the Cat.
  • Page 83 2-77 Adjustment of magnetic/digital subwoofer level. Systems with subwoofers but no Le or Re speakers. Select format 42 (Dolby Stereo 70 mm). Select Center on the Cat. No.85, using a RTA observe the level of the pink noise from the center channel, note the amplitude on the display.
  • Page 84 A low level on Future 11 indicates that an optical film format is selected. Future 11 is used to cause the DA20 to assert format 10 automatically when the DA20 is in Auto Digital Mode and valid digital audio is present. See the DA20 Users’ Manual for specific information on the Auto Digital feature.
  • Page 85 2-79 DA20 J6 Cat,. No. 493 DB25 Male DB25 Female Pin Number Pin Number / CP200 Backplane 1 CTRL0 1 SW Control / B21 of SK13 (Soldered) 2 CTRL1 2 Assert GO Button 3 CTRL2 3 Format A Assert 4 CTRL3...
  • Page 86 2-80 Figure 2.16 Cat. No.517 Block Diagram...
  • Page 87 2-81 Figure 2.17 Cat. No.560 Block Diagram...

  • Page 88: Installation Of Da20 With Cp45

    2-82 2.5.4 Installation of DA20 with CP45 An Adapter board, Cat. No. 545, is available for connecting the DA20 to the CP45 rear panel connector J10. Refer to the CP45 wiring Diagram fold-out, Figure 2.18. Audio from DA20 to CP45 (This cable is Available from Dolby Laboratories as Part No.
  • Page 89 Format 10 depending on which mode the DA20 is in. In all cases, the control lines must be low for a minimum of 80ms to be recognized as valid format assertions. The DA20 will assert various control lines depending on which mode is selected on the DA20.

  • Page 90: Installation Of Da20 With Cp500

    2-85 2.5.5 Installation of DA20 with CP500 Refer to the CP500 wiring Diagram fold-out, Figure 2.19 CP500 to DA20 Connection Tables Audio from DA20 to CP500 DA20 CP500 CP Audio Out Conn. J8 6 Channel Input Conn (DB25) (DB25 Male) Pin No.
  • Page 91 Format 10 depending on which mode the DA20 is in. In all cases, the control lines must be low for a minimum of 80ms to be recognized as valid format assertions. The DA20 will assert various control lines depending on which mode is selected on the DA20.

  • Page 92: Section 3 Cat. No. 700 Digital Soundhead Alignment

    Connect a probe from Channel 1 of a 20MHz or greater bandwidth oscilloscope to the VIDEO Test Point (TP1) on the Cat. No.670 Video Acquisition Card in slot 12 of the DA20(leftmost card), with the ground lead attached to VGND (TP2, just below TP1).

  • Page 93: Focus Adjustment

    Adjust the Ch 2 vertical trace position to move the trace off the screen. It is not necessary to view this signal once triggering has been established. Cat. No.670 Video Board (DA20 slot 12) Test Points: VIDEO TP1 (white) The CCD video signal...

  • Page 94: Exciter Lamp Level Confirmation And Adjustment

    Exciter Lamp Level Confirmation and Adjustment The output voltage of the lamp power supply is factory-set to be between 9.5 and 10 volts. Lamp intensity has a direct relationship to the video signal voltage. The acceptable range for the peak video signal voltage (of unobstructed light through the perf hole) is between 2.7 and 5 volts (see figure in Section 3.3).

  • Page 95: Optical Alignment

    CLAMP SCREW LATERAL TENSION ARM ADJUSTMENT SCREW SPRING Optical Alignment The soundhead is optically aligned at manufacture and should not require adjustment unless the CCD circuit board has been moved or replaced (the CCD sensor is located on the CCD circuit board. Optical alignment of the sensor depends on the position of the circuit board).
  • Page 96 Rotate the CCD circuit board assembly clockwise and counterclockwise and observe the LEDs on the Cat. No.671 boards in slots 2 and 3 of the DA20. Center the rotation of the CCD circuit board assembly between the angles at which synchronization pattern finding begins to fail.

  • Page 97: Cinema Processor Type Selection

    Do Not Use (LEDs will Flash) Do Not Use (LEDs will Flash) When the CP Type switch is set to one of the Auto Digital Enabled positions, the DA20 will automatically assert a Format 10 command to the cinema processor if the DA20 detects that the cinema processor is in a film format and there is valid Dolby Digital audio available.
  • Page 98 Processor Interface Card (located between the analog LED and the proj. 1 LED of the C.P. Status slot in the front panel of the DA20). SW1 (upper), SW2 (center), and SW3 (lower) select a delay from 016 to 528 film perforations. SW1 selects hundreds of perfs, and has the largest effect on delay, SW2 sets tens of perfs, and SW3 single perfs.
  • Page 99 Card located between the analog signal presence LED and the Dolby Digital LED of the C.P. Status slot in the front panel of the DA20. Set SW5 to the position 9,A, or B depending on the Cinema Processor type (see section 4.1) Monitor audio from the center channel of the DA20 while simultaneously monitoring audio from the analog tracks through the Cinema Processor.
  • Page 100 100 110 120 130 140 150 Delay (ms) Switch setting Width (in feet) Length feet) Width (in meters) Length (meters)

  • Page 101: Section 5 Theory Of Operation

    5.1 DA20 Basic Functions 5.2 Discussion of Changeover Technique 5.3 Format Control 5.4 Auxiliary Data Channel DA20 Basic Functions The basic functions of the DA20 are: Video Acquisition Sync Finding Thresholding and Bit Packing Error Correction and De-interleaving FIFO Buffering and DAC Clock Generation...
  • Page 102 Soundhead Delay A delay is required in the DA20 to compensate for the time between when the data is read (at the Digital Soundhead) and when the audio is to be reproduced in sync. with the picture.

  • Page 103: Format Control

    DA20 assumes no analog track is playing. The motor start signals are used to signal the DA20 in advance of a changeover in order that the video front end can switch to video from the incoming reel prior to the actual picture changeover. The changeover to the incoming projector CCD signal will be made at a time after the Motor Start signal equal to (7 seconds minus the fixed delay value.) Removal of the Motor Start...
  • Page 104 CP200: When the CP Type switch is set to position 3 (Auto Digital mode) and the DA20 is connected to the CP200 using a Cat. No.493 CP200 Auto Digital Interface Card, the DA20 will automatically assert Format 10 when it detects that the CP200 has been set to Formats 01, 04 or 05.

  • Page 105: Auxiliary Data Channel

    DCE with TXD on pin 2 and signal common on pin 7. Pins 4 and 6 are shorted, as are pins 7 and 8, to allow direct connection to a standard PC serial port. The connector case is wired to chassis ground. DA20 J3 DB9 Female Pin assignments 1 n.c.

  • Page 106: Section 6 Operating Instructions

    SECTION 6 OPERATING INSTRUCTIONS How to Identify Sound Tracks on Prints Film Threading Displays Format Control Auliliary Data Channel Two Projector Changeover Operation Operation With An Automation System How to Identify Sound Tracks on Prints A Dolby Digital film print or a stereo optical print (A-Type or SR), or a mono optical print should be identified as such on both the film can and leader.

  • Page 107: Displays

    Figure 6.2 Film threading Displays The DA20 has eight slots in the front panel to allow sets of LEDs to be visible, indicating the activity of various circuits. The large slot in the center is used as an error rate display on a seven segment LED.
  • Page 108 These Indicators represent the decoded analog signal level present at the output of the DA20. In a system using a CP200 Cinema Processor, analog audio from the cinema processor is routed through the DA20 to allow switching between the analog and the digital tracks.

  • Page 109: Format Control And Auto Digital Modes

    The DA20 can operate in either of two basic modes: Auto Digital and Auto Digital Disabled. These are described below: When the CP Type switch on the DA20 is set to Auto Digital mode for a particular cinema processor type, the DA20 will automatically assert Format 10 and switch the Cinema Processor to Format 10 under certain conditions.
  • Page 110 The operation of the DA20 with each Cinema Processor is described separately below: CP55 When the CP Type switch is set to position 1, the DA20 will operate in Auto Digital mode. In this mode, the DA20 will automatically switch the CP55 to Format 10 if the following conditions exist: •...
  • Page 111 To re-enable the automatic selection of Format 10 after it has been disabled by pushing the Format 05 button, either the DA20 must be turned off and then on again or the CP Type selector switch must be rotated away from and back to position 2.

  • Page 112: Auxiliary Data Channel

    CP200 to play the analog SR track. Auto-digital mode can not be re-enabled unless the DA20 is turned off and then on again or the CP Type switch is rotated out of and back into position 3. This will cause the DA20 to re-scan the CP200 format selectors and look for Format 10 again and therefore should not be done while film is playing.

  • Page 113: Operation With An Automation System

    When used with a CP200, the automation system controls the Cinema Processor, which sends a signal to the DA20 indicating that digital sound is desired. The DA20 responds with a signal indicating that digital audio has been decoded and is present on its output lines, or that such decoding is not possible.

  • Page 114: Section 7 Maintenance And Adjustments

    SECTION 7 MAINTENANCE AND ADJUSTMENTS Remove power before Digital Soundhead Maintenance removing circuit boards. Print Cleanliness Always use static Adjustments precautions. Digital Soundhead Maintenance The Cat. No.700 Digital Soundhead should be kept clean and free of dust and dirt for best performance, just like your analog soundhead.

  • Page 115: Print Cleanliness

    Digital print format has robust error correction information encoded along with the audio data, and the DA20 uses a powerful digital error correction technique, allowing the data to be read perfectly even if scratches and dirt are present. However, best performance will be obtained if the print is kept clean.

  • Page 116: Section 8 Unit Servicing / In Case Of Difficulty

    Refer to page 2-1 for information on replacing the exciter lamp. • If you are sure that power is applied to the DA20, but no LEDs on the front panel are on, check the fuse in the power entry module on the rear of the DA20. If it appears blown, replace with a spare fuse of the type and value specified on the rear panel of the DA20.

  • Page 117: Problem Identification

    CP500—Rotate the CP Type switch located on the DA20 front panel to position 6. If One Channel Fails or is Distorted This is unlikely to be a fault of the DA20. Check for analog audio path continuity. If the problem is isolated to the DA20, contact your authorized Service Engineer.
  • Page 118 12 screws and the front panel MUST be replaced and tightened securely. All cards must be present in the DA20 for normal operation. A circuit trace on each card passes a signal [LINK] to the Cat. No.673 System Services card which allows normal operation.
  • Page 119 Normal display during power up C Performing checksum on Flash Rom contents—displays briefly (about 1/10 second) Resetting all cards in the DA20 (1/2 second) L Loading system code (a few seconds) — Successful system load, film not running If the system does not load successfully, see Displays Indicating Trouble section below.

  • Page 120: Determining Software Revision No

    The System Services Card (Cat. No. 673) in slot 15 has a rotary switch (SW1) located directly under the alphanumeric display which allows the DA20 to be switched into various test modes used in manufacture and test. The switch should be set to “0” for normal operation.

  • Page 121: Starting And Program Loading

    AC3 baseline Serial port ROM load The software in the DA20 is subject to continual improvement, both at the factory and by “dynamic loading” from film in the field. Therefore, the revision numbers for the modules may be higher than those shown above, or lower for units made before the date shown.
  • Page 122 (failed card or unplugged card, for example). Failures in Digital Equipment A failure in the DA20 will nearly always affect all channels. Therefore if only some of the audio channels are affected, the problem probably lies elsewhere.

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