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Dolby Laboratories CP65 Oscilloscope Traces, Rta Display, A-ChainAlignment Procedures, Action

Models: CP65

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Page 34

OSCILLOSCOPE TRACES

		4-14
		A-Chain Alignment Procedures
b. Optical Preamplifier Adjustments

Step	Action	Indication
No.	Action	Indication
No.
12		OSCILLOSCOPE TRACES
		OSCILLOSCOPE TRACES

✓

		RT
Cat. No. 240A
Proj. 1 Status		IN
Proj. 1 Status
RV101 Gain	L
RV102 hf	L
RV102 hf
RV201 Gain	R		x
RV202 hf	R
RV202 hf
TP501 L tp	SIGNAL	X		Out of phase
L	SIGNAL			Out of phase
	PRESENT	Y
R		Y
R
TP502 R tp
RV301 Gain	L
RV302 hf	R
RV401 Gain	R	SCOPE
RV402 hf		SCOPE
Proj. 2 Status		X-Y
TP503 GND		X-Y
TP503 GND		MODE
		MODE
			x	Incorrect azimuth
				Incorrect azimuth

13

dB +10

+5

INTO	✓
FOCUS

0

–5

OUT OF

FOCUS X

–10

.05

.1

.2

.4

.8

1.6

3.15

6.3

12.5

kHz

RTA DISPLAY

4-15

A-Chain Alignment Procedures

b. Optical Preamplifier Adjustments

Notes

Remove the Cat. No. 97 film and thread and play the pink noise on the Cat. No. 69 film (emulsion away from screen). Connect the RTA to the left test point TP501 L on the Cat. No. 240A.

Switch the oscilloscope to the X/Y mode and adjust the azimuth of the projector optics for the narrowest diagonal trace. (Blooming at the ends of the trace may be caused by improper lighting of the edges of the optical tracks. If necessary, repeat steps 8 and 9 above, or step 5 on page 4-4 to reduce such blooming to a minimum.)

xx

Not enough light	Uneven light on cell
on one channel

Then, while observing the trace on the RTA, adjust the focus of the sound track lens for the best high frequency response. The trace shown in the example is ideal; merely attempt to obtain the best response. The azimuth and focus adjustments interact so you must repeat Steps 12 and 13 until no further adjustments are required.

Image 34

Dolby Laboratories CP65 Oscilloscope Traces, Rta Display, A-ChainAlignment Procedures, b. Optical Preamplifier Adjustments

Contents

Installation and Alignment Instructions Model CP65 Cinema ProcessorDolby Laboratories Inc Dolby Laboratories Inc U.S. HeadquartersU.K. European Office 100 Potrero Avenue San Francisco, CA TelephoneINTRODUCTION Table of ContentsINITIAL SET-UPAND INSTALLATION EQUIPMENT REQUIREDAPPENDIX C APPENDIX AAPPENDIX B APPENDIX D04 Dolby Stereo A-type 05 Dolby Stereo SR INTRODUCTIONCP65 60 Non-syncPage 1 Dolby Tone and Pink Noise - Cat. No SECTION EQUIPMENT REQUIRED2 1kHz, 100% Modulation, Left/Right - Cat. No 4Stereo Optical Surround Level - Cat. No TEST FILM3SMPTE Buzz Track JIFFYSECTION INITIAL SET-UPAND INSTALLATION Acceptable SettingVoltage Voltage RangeCat. No Cat. No. 242, B-ChainCard Cat. No. 249, Power Supply ModuleJ5 J6 J7 J8 Cat. No. 443, Control Logic Card J3 INCP65 Backplane Standard CP65 or CP65AIn 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 J24 CP65-300J1 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 Slot selected projector. Electronic switches selectCard Descriptions Card2 4 Channel Decoder Two-channelNoiseReduction Module 7,8,9Function SlotCard Cat. NoFuse Voltage SettingInternational TypeIMPORTANT SAFETY NOTICE IEC NOTICESGB F D I E S NL IMPORTANT - NOTE DE SECURITE3.Room lighting dimmer controls SCR-TYPE HUM PROBLEMSModel CP65 With CP65 FADER turned up and format 04 selected 1. Aligning the A-Chain SECTION AN OVERVIEW OF THE ALIGNMENT PROCEDURE2. 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 Action a. Preliminary Proceduresa. Preliminary Procedures Notes Indicationa. Preliminary Procedures Notes A-ChainAlignment Proceduresa. Preliminary Procedures ActionAction b. Optical Preamplifier Adjustmentsb. Optical Preamplifier Adjustments Notes Indicationb. Optical Preamplifier Adjustments Notes A-ChainAlignment Proceduresb. Optical Preamplifier Adjustments Actionb. Optical Preamplifier Adjustments L L R R L L R RCAT NO b. Optical Preamplifier Adjustments NotesCAT. NO. 97 TEST FILM ActionIndicationn REPEATA-ChainAlignment Procedures OSCILLOSCOPE TRACESRTA DISPLAY b. Optical Preamplifier AdjustmentsA-ChainAlignment Procedures 12 ANDREPEAT b. Optical Preamplifier Adjustmentsb. Optical Preamplifier Adjustments CAT NOFOR PROJECTOR NO. REPEAT 1 → b. Optical Preamplifier Adjustments Notesc. Magnetic Preamplifier Adjustments Magnetic Alignmentc. Magnetic Preamplifier Adjustments A-ChainAlignment ProceduresMagnetic Alignment SECTION B-CHAINALIGNMENT bypass a. Setting Room Equalizationa. Setting Room Equalization Notes Actiona. Setting Room Equalization Notes Loudspeakers and Crossoversa. Setting Room Equalization ActionGeneral bypassAmplifiers a. Setting Room EqualizationAction B-ChainAlignment Proceduresa. Setting Room Equalization Notes Indicationa. Setting Room Equalization Notes REPEATa. Setting Room Equalization Actiona. Setting Room Equalization Notes B-ChainAlignment Proceduresa. Setting Room Equalization Actiona. Setting Room Equalization Notes Do not adjusta. Setting Room Equalization ActionAction a. Setting Room Equalizationa. Setting Room Equalization Notes IndicationL 14 → 21 R 14 → b. Adjusting L,C,R Gainb.Adjusting L,C,R Gain 22REPEAT79 dBC c. Setting Mono Gainc. Setting Mono Gain Notes ActionB-ChainAlignment Procedures d. Subwoofer Alignment Cat. Nod. Subwoofer Alignment Cat. No. Notes Actiond. Subwoofer Alignment Cat. No 90 dBCB-ChainAlignment Procedures Actiond. Subwoofer Alignment Cat. No FROMd. Subwoofer Alignment Cat. No ActionAction Select format 04 Dolby Stereo A-Typed. Subwoofer Alignment Cat. No REPEATd. Subwoofer Alignment Cat. No SAME ASd. Subwoofer Alignment Cat. No Actione. Surround Equalization Alignment Cat. No Re Se. Surround Equalization Alignment Cat. No Actione. Surround Equalization Alignment Cat. No ActionAction e. Surround Equalization Alignment Cat. NoREPEAT e. Surround Equalization Alignment Cat. No 88 dBCAction Action B-ChainAlignment Procedurese. Surround Equalization Alignment Cat. No Indicationmsec f. Adjustment of Surround DelayThumbwheel Switch Settingxx dBC g. Adjustment of Bypass Gaing. Adjustment of Bypass Gain Notes B-ChainAlignment Proceduresg. Adjustment of Bypass Gain FROM xx dBC -3dB yy dBCB-ChainAlignment Procedures g. Adjustment of Bypass Gain NotesPress the format 60 non sync switch h. Adjustment of Non-syncGainh. Adjustment of Non-syncGain Notes ActionAction h. Adjustment of Non-syncGainh. Adjustment of Non-syncGain Notes Indication5REPEAT PAGE 5-20STEP i. Adjustment of Mono Gain and Equalizationi.Adjustment of Mono Gain and Equalization Notes B-ChainAlignment Proceduresj. Final Checks Press the format 04 Dolby Stereo A-type switchJIFFY TEST FILM j. Final Checks NotesSECTION REFERENCE DIAGRAMS Cat. No. 222 Dual Noise Reduction Module INPUTS OUTPUTSPage Cat. No. 242 B-ChainFacilities Card Cat. No. 249 Power Supply Card Cat. No. 259 Transformer Module INPUTS OUTPUTSCat. No. 443 Control Logic Card +24V CP65 POWER DISTRIBUTION TABLECat. No +15VAPPENDIX A CHECKING PHASING OF SPEAKERS 10,000 Frequency in Hz5,000 20,0001.Operation APPENDIX C CP65M MONO INSTRUCTIONS2.Cat. No. 327A Circuit Description C.2 Schematic Cat. No. 327A A3C2984 revTerminal Block TB1 APPENDIX D BACKPLANE CONNECTIONS LISTCP65 Backplane Connections Terminal Block TB2D connector J18