Dolby Laboratories CP65 manual

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This installation and alignment manual covers the procedures necessary to ensure that the theatre sound system is accurately aligned to standards that have been established by Dolby Laboratories. Following these procedures will ensure that the theatre sound system will accurately reproduce the soundtrack as the director and sound mixers intended.

The Dolby Cinema Processor is the central element of the theatre sound system. The projector, the Dolby Processor, the power amplifiers and the loudspeakers, as well as the auditorium itself, must be considered when aligning the system for optimum performance.

The system alignment procedure is divided into two parts—the A-chain alignment which covers the projector, optical preamplifier, and Dolby noise reduction adjustments—and the B- chain alignment which covers the portions of the system from the room equalization circuits to the CP65 fader through to the loudspeakers.

The alignment instructions in this Manual are presented in three columns. The first column, Action, contains a drawing of the item to be adjusted and a caption containing a brief description of the action to be taken. The second column, Indication, contains a visual indication of the desired results, where applicable. The third column, Notes, contains information which amplifies and supplements the other two columns.

If you are familiar with alignment of other Dolby Cinema Processors you need to follow only the information in the first two columns. If you are unfamiliar with the equipment or face special situations that require complete information you should consult the Notes column.

CAUTION

This Installation Manual is for use by qualified personnel only. To avoid electric shock do not perform any servicing other than that contained in the Operator's Guide unless you are qualified to do so.

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Contents Model CP65 Cinema Processor Dolby Laboratories Inc Headquarters Table of Contents Section Reference Block Diagrams Introduction Page Section Equipment Required Smpte Buzz Track Stereo Optical Surround Level Cat. No Jiffy Test Film Cat. No 2 Listen . . . Film Cat. NoSection Initial SET-UP and Installation Voltage Acceptable Setting Voltage Range Fuse Type Next, check the jumpers in the following locations Cat. No , Power Supply Module Cat. No , B-Chain CardCat. No , Control Logic Card J2 NON-SYNCCP65 Backplane Standard CP65 or CP65ACP65-300 High Low Subwoofer subwoofer Output output These Modules are Necessary for Bypass Operation Reduction Module Slot Card Function Cat. NoTwo-channel Noise Channel DecoderContains a semi-regulated power supply with Voltage Setting Fuse Type InternationalIEC Notices HUM Problems Room lighting dimmer controls SCR-TYPEPage Section AN Overview of the Alignment Procedure Aligning the B-ChainPage Page Section Chain Alignment Preliminary Procedures Action IndicationLamp Voltage Optical Preamplifier Adjustments Chain Alignment Procedures Optical Preamplifier Adjustments 222 CAT. no Test Film Oscilloscope Traces Repeat CAT no Repeat 1 →Magnetic Preamplifier Adjustments Magnetic Alignment 100mV Section Chain Alignment Setting Room Equalization BypassLoudspeakers and Crossovers Amplifiers GeneralChain Alignment Procedures OffRepeat ActionChain Alignment Procedures Setting Room Equalization Do not adjust Paul Setting Room Equalization b. Adjusting L,C,R Gain 14 → 21 R 14 →Setting Mono Gain 79 dBCChain Alignment Procedures Subwoofer Alignment Cat. No 90 dBC 85 dBCFrom Step NoSelect format 04 Dolby Stereo A-Type Same AS 441Surround Equalization Alignment Cat. No Surround Equalization Alignment Cat. No Notes Cat. No 441Desired 88 dBC Bypass Adjustment of Surround Delay Thumbwheel SwitchMsec Setting Chain Alignment Procedures Adjustment of Bypass Gain Xx dBCFrom Xx dBC -3 dB Yy dBCAdjustment of Non-sync Gain Press the format 60 non sync switchAuto Freq Adjustment of Mono Gain and Equalization Notes Repeat page 5-20 StepChain Alignment Procedures Final Checks Press the format 04 Dolby Stereo A-type switchSection Reference Diagrams Cat. No Dual Noise Reduction Module Inputs Cat. No Optical Bass Extension and Surround Equalizer Card Cat. No B-Chain Facilities Card Cat. No Power Supply Card Cat. No Transformer Module Inputs Cat. No Control Logic Card Cat. No +24V +15V 15V +12B+15M Appendix a Checking Phasing of Speakers Appendix B Effect of Changes in Slit Height on Slit Losses Appendix C CP65M Mono Instructions OperationCat. No a Circuit Description Schematic Cat. No a Appendix D Backplane Connections List Terminal Block TB3Connector J18