Dolby Laboratories CP65 manual Section Initial SET-UP and Installation

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2-1

SECTION 2

INITIAL SET-UP AND INSTALLATION

Before you remove or replace the Cat. No. 240A Optical Pre-Amp or the Cat. No. 249 Power Supply Card, first disconnect AC power from the CP65 to protect the speakers and the CP65 from damage. For all other modules in the CP65, first switch to BYPASS; you can then safely remove or replace the desired card without disconnecting power from the CP65.

Do NOT connect the CP65 to mains power until all connections have been made and all jumpers have been installed (see STEP 9 later in this section).

STEP 1 If air-conditioning noise is audible in the theatre, arrange for lubrication of the motor, fan bearings, adjustment of belts and drives, and cleaning of filters to reduce the ambient noise to a minimum.

If the CP65 replaces an existing cinema sound system, play a typical film before you remove the old system so you will have a benchmark for comparison to the new system and as a check of the positioning of the exciter lamp, the focusing of the sound track lens, and the condition of the solar cell.

Before you run the film:

•Verify that the existing power amplifiers are in good working order.

•Verify that the existing speakers are in good working order, and that there is no loose or missing hardware or structural members in the enclosures.

•Verify that all wiring is present and properly connected and that crossovers are operating and are correctly adjusted.

•Check the phasing of the speaker connections (see Appendix A).

•Verify that there are adequate earth (ground) connections.

•Verify that radio interference problems are adequately resolved.

STEP 2 While you are running the film, listen carefully in various parts of the theatre for audio system problems:

•Hum.

•Noise, clicks, pops.

•Distortion.

•Poor tonal balance (lack of high-frequency or bass content).

These problems must be resolved before you can proceed to the next step in the installation.

STEP 3 To avoid heat problems, do not locate the CP65 immediately above or below the power amplifiers.

Always leave a 1U (43 mm, 1.75") space above and below the CP65 to provide adequate ventilation. Install an air guide or baffle to deflect hot air from equipment below the CP65.

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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 Jiffy Test Film Cat. No 2 Listen . . . Film Cat. No Smpte Buzz Track Stereo Optical Surround Level Cat. NoSection Initial SET-UP and Installation Voltage Acceptable Setting Voltage Range Fuse Type Next, check the jumpers in the following locations Cat. No , B-Chain Card Cat. No , Power Supply ModuleJ2 NON-SYNC Cat. No , Control Logic CardStandard CP65 or CP65A CP65 BackplaneCP65-300 High Low Subwoofer subwoofer Output output These Modules are Necessary for Bypass Operation Two-channel Noise Slot Card Function Cat. NoReduction Module Channel DecoderContains a semi-regulated power supply with International Voltage Setting Fuse TypeIEC Notices Room lighting dimmer controls SCR-TYPE HUM ProblemsPage Aligning the B-Chain Section AN Overview of the Alignment ProcedurePage Page Section Chain Alignment Action Indication Preliminary ProceduresLamp Voltage Optical Preamplifier Adjustments Chain Alignment Procedures Optical Preamplifier Adjustments 222 CAT. no Test Film Oscilloscope Traces Repeat Repeat 1 → CAT noMagnetic Preamplifier Adjustments Magnetic Alignment 100mV Section Chain Alignment Bypass Setting Room EqualizationLoudspeakers and Crossovers General AmplifiersOff Chain Alignment ProceduresAction RepeatChain Alignment Procedures Setting Room Equalization Do not adjust Paul 14 → 21 R 14 → Setting Room Equalization b. Adjusting L,C,R Gain79 dBC Setting Mono GainChain Alignment Procedures Subwoofer Alignment Cat. No 85 dBC 90 dBCStep No FromSelect format 04 Dolby Stereo A-Type 441 Same ASSurround Equalization Alignment Cat. No Cat. No 441 Surround Equalization Alignment Cat. No NotesDesired 88 dBC Bypass Adjustment of Surround Delay Thumbwheel SwitchMsec Setting Xx dBC Chain Alignment Procedures Adjustment of Bypass GainXx dBC -3 dB Yy dBC FromPress the format 60 non sync switch Adjustment of Non-sync GainAuto Freq Repeat page 5-20 Step Adjustment of Mono Gain and Equalization NotesPress the format 04 Dolby Stereo A-type switch Chain Alignment Procedures Final ChecksSection 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 Terminal Block TB3 Appendix D Backplane Connections ListConnector J18