Manuals / Dolby Laboratories / Home Audio / Stereo Amplifier

Dolby Laboratories CP65 manual Action, Indicationn, CAT. NO. 97 TEST FILM, Repeat

Models: CP65

1 82

Download 82 pages 36.23 Kb

Page 33

Action

4-12

A-Chain Alignment Procedures

b. Optical Preamplifier Adjustments

Step			Action		Indicationn
No.			Action		Indicationn
No.
9
			CAT. NO. 97 TEST FILM
					OSCILLOSCOPE TRACE
10				CAT NO.
				222	Cat. No.
					240A
					Proj. 1
					GAIN
					Lt
					hf	Lt
					GAIN	Lt
				Lt	GAIN
					Rt
					hf
					Lt tp
					Lt tp
					Lt	Rt
					signal	Rt
					signal
					present
					Rt
				Rt	Rt tp
				Rt	GAIN
					GAIN
					Lt
					hf
					GAIN
					Rt
					hf
					Proj. 2
					gnd
	L R
11	REPEAT	8	AND 9

4-13

A-Chain Alignment Procedures

b. Optical Preamplifier Adjustments

Notes

Remove the SMPTE Buzz Track Film and thread and play the Cat. No. 97 Stereo Cell Alignment Film. While the film is playing, look at the oscilloscope. If a large amount of crosstalk is present, loosen the stereo solar cell head and move the head from side to side until the crosstalk both left-to-right and right-to-left are both at a minimum and are equal.

(The right channel is the track toward the outside of the projector.) You should be able to adjust the position of the cell to obtain better than 20 dB of crosstalk rejection (10:1 voltage ratio) both left-to-right and right-to-left. Setting the gain of both channels of the preamplifier to a known setting such as minimum or maximum gain will assist in judging when the crosstalk is equal right-to-left and left-to-right NOTE: On some projectors, it may be necessary to stop the film to adjust the position of the cell.

Lock the cell bracket into position after completing this adjustment. Check that the crosstalk has not changed as the bracket was tightened.

Verify that the outputs of the right and left solar cells are properly connected per the diagram in Step 2. Then place a white card over the right solar cell (nearer the outside of the projector) and verify that the level of the right channel drops — as indicated by the R LED on the Cat. No. 222 card, and the R LED on the Cat. No. 240A card.

Repeat the SMPTE Buzz Track alignment in Step 8. If the film or optics/exciter lamp position must be readjusted, repeat Step 9. The optimum setting is attained when no further adjustments are required in Steps 8 and 9.

Image 33

Dolby Laboratories CP65 manual Action, Indicationn, CAT. NO. 97 TEST FILM, Repeat

Contents

Model CP65 Cinema Processor Installation and Alignment InstructionsU.K. European Office Dolby Laboratories Inc U.S. HeadquartersDolby Laboratories Inc 100 Potrero Avenue San Francisco, CA TelephoneINITIAL SET-UPAND INSTALLATION Table of ContentsINTRODUCTION EQUIPMENT REQUIREDAPPENDIX B APPENDIX AAPPENDIX C APPENDIX DCP65 INTRODUCTION04 Dolby Stereo A-type 05 Dolby Stereo SR 60 Non-syncPage SECTION EQUIPMENT REQUIRED 1 Dolby Tone and Pink Noise - Cat. No2 1kHz, 100% Modulation, Left/Right - Cat. No 3SMPTE Buzz Track TEST FILM4Stereo Optical Surround Level - Cat. No JIFFYSECTION INITIAL SET-UPAND INSTALLATION Voltage SettingAcceptable Voltage RangeCat. No Cat. No. 249, Power Supply Module Cat. No. 242, B-ChainCardJ5 J6 J7 J8 J3 IN Cat. No. 443, Control Logic CardStandard CP65 or CP65A CP65 BackplaneCP65-300 In a CP65-300when Cat. No. 300 modules are fitted in place of the normal Cat. No. 350 modules J16 and J18 should be rotated so that the words “Format 42” appears the right way up. With J24 in the “NR” position input signals will be A-typedecoded when the Mag/Aux format is selected. With J24 in the “NO NR” position signals pass through the noise reduction modules but the processing will be turned off. If both of these processing options are required frequently an external switch may be connected to J24J1 Optical Bass Extension output level sets the output level range for the subwoofer channel. In the HIGH position J1 is set at the factory for a power amplifier input sensitivity of between 90 mV and 1.23 V. If the power amplifiers used in the installation are very sensitive 10 mV to 100 mV input sensitivity, it may be necessary to set J1 to the LOW position. If you are unsure of the sensitivity of your power amplifiers set J1 to the LOW position initially. If the high output position is required this will be determined during OBE alignment Card Descriptions selected projector. Electronic switches selectSlot CardReduction Module Two-channelNoise2 4 Channel Decoder 7,8,9Card SlotFunction Cat. NoInternational Voltage SettingFuse TypeGB F D I E S NL IEC NOTICESIMPORTANT SAFETY NOTICE IMPORTANT - NOTE DE SECURITEHUM PROBLEMS 3.Room lighting dimmer controls SCR-TYPEModel CP65 With CP65 FADER turned up and format 04 selected SECTION AN OVERVIEW OF THE ALIGNMENT PROCEDURE 1. Aligning the A-Chain2. Aligning the B-Chain and with a broad range of speakers. Accurate equalization requires the use of standardized acoustic measurement procedures Many loudspeakers used in theatres are far from ideal and require boosting of the low- and high-frequencyextremes in order to produce an approximation of the standard reference response curve. Bass and treble controls-centeredon the turnover points of typical loudspeakers-liftthe ends of the spectrum without the need for large amounts of narrow- band boost from the third-octavecontrols in the Cat. No. 64 cards. The third-octavecontrols are used for minor adjustments that are required to smooth the frequency response curve SECTION A-CHAINALIGNMENT a. Preliminary Procedures Notes a. Preliminary ProceduresAction Indicationa. Preliminary Procedures A-ChainAlignment Proceduresa. Preliminary Procedures Notes Actionb. Optical Preamplifier Adjustments Notes b. Optical Preamplifier AdjustmentsAction Indicationb. Optical Preamplifier Adjustments A-ChainAlignment Proceduresb. Optical Preamplifier Adjustments Notes ActionCAT NO L L R R L L R Rb. Optical Preamplifier Adjustments b. Optical Preamplifier Adjustments NotesIndicationn ActionCAT. NO. 97 TEST FILM REPEATRTA DISPLAY OSCILLOSCOPE TRACESA-ChainAlignment Procedures b. Optical Preamplifier AdjustmentsREPEAT 12 ANDA-ChainAlignment Procedures b. Optical Preamplifier AdjustmentsFOR PROJECTOR NO. REPEAT 1 → CAT NOb. Optical Preamplifier Adjustments b. Optical Preamplifier Adjustments NotesMagnetic Alignment c. Magnetic Preamplifier AdjustmentsA-ChainAlignment Procedures c. Magnetic Preamplifier AdjustmentsMagnetic Alignment SECTION B-CHAINALIGNMENT a. Setting Room Equalization Notes a. Setting Room Equalizationbypass Actiona. Setting Room Equalization Loudspeakers and Crossoversa. Setting Room Equalization Notes ActionAmplifiers bypassGeneral a. Setting Room Equalizationa. Setting Room Equalization Notes B-ChainAlignment ProceduresAction Indicationa. Setting Room Equalization REPEATa. Setting Room Equalization Notes Actiona. Setting Room Equalization B-ChainAlignment Proceduresa. Setting Room Equalization Notes Actiona. Setting Room Equalization Do not adjusta. Setting Room Equalization Notes Actiona. Setting Room Equalization Notes a. Setting Room EqualizationAction Indicationb.Adjusting L,C,R Gain b. Adjusting L,C,R GainL 14 → 21 R 14 → 22REPEATc. Setting Mono Gain Notes c. Setting Mono Gain79 dBC Actiond. Subwoofer Alignment Cat. No. Notes d. Subwoofer Alignment Cat. NoB-ChainAlignment Procedures ActionB-ChainAlignment Procedures 90 dBCd. Subwoofer Alignment Cat. No Actiond. Subwoofer Alignment Cat. No FROMd. Subwoofer Alignment Cat. No Actiond. Subwoofer Alignment Cat. No Select format 04 Dolby Stereo A-TypeAction REPEATd. Subwoofer Alignment Cat. No SAME ASd. Subwoofer Alignment Cat. No Actione. Surround Equalization Alignment Cat. No Re Se. Surround Equalization Alignment Cat. No ActionAction e. Surround Equalization Alignment Cat. Noe. Surround Equalization Alignment Cat. No ActionREPEAT 88 dBC e. Surround Equalization Alignment Cat. NoAction e. Surround Equalization Alignment Cat. No B-ChainAlignment ProceduresAction IndicationThumbwheel Switch f. Adjustment of Surround Delaymsec Settingg. Adjustment of Bypass Gain Notes g. Adjustment of Bypass Gainxx dBC B-ChainAlignment ProceduresB-ChainAlignment Procedures FROM xx dBC -3dB yy dBCg. Adjustment of Bypass Gain g. Adjustment of Bypass Gain Notesh. Adjustment of Non-syncGain Notes h. Adjustment of Non-syncGainPress the format 60 non sync switch Actionh. Adjustment of Non-syncGain Notes h. Adjustment of Non-syncGainAction Indicationi.Adjustment of Mono Gain and Equalization Notes i. Adjustment of Mono Gain and Equalization5REPEAT PAGE 5-20STEP B-ChainAlignment ProceduresJIFFY TEST FILM Press the format 04 Dolby Stereo A-type switchj. Final Checks j. Final Checks NotesSECTION REFERENCE DIAGRAMS Cat. No. 222 Dual Noise Reduction Module OUTPUTS INPUTSPage Cat. No. 242 B-ChainFacilities Card Cat. No. 249 Power Supply Card Cat. No. 259 Transformer Module OUTPUTS INPUTSCat. No. 443 Control Logic Card Cat. No CP65 POWER DISTRIBUTION TABLE+24V +15VAPPENDIX A CHECKING PHASING OF SPEAKERS 5,000 Frequency in Hz10,000 20,000APPENDIX C CP65M MONO INSTRUCTIONS 1.Operation2.Cat. No. 327A Circuit Description A3C2984 rev C.2 Schematic Cat. No. 327ACP65 Backplane Connections APPENDIX D BACKPLANE CONNECTIONS LISTTerminal Block TB1 Terminal Block TB2D connector J18