Dolby Laboratories CP65 manual Repeat

Page 35

 

 

 

4-16

 

 

 

 

A-Chain Alignment Procedures

 

b. Optical Preamplifier Adjustments

 

Step

 

Action

 

Indication

No.

 

 

 

 

 

 

14

 

 

 

 

 

 

 

RTA

 

Cat. No. 240

 

 

 

 

 

 

IN

 

Proj. 1

Status

 

 

 

RV101

Gain

L

 

 

RV102 hf

 

 

 

 

 

RV201

Gain

R

 

 

RV202 hf

 

 

 

 

 

TP501 L tp

 

X

 

 

L

SIGNAL

 

 

 

 

 

 

 

 

PRESENT

Y

 

 

R

 

 

 

 

 

 

TP502 R tp

 

 

 

RV301 Gain

L

 

 

RV302 hf

R

 

 

RV401 Gain

SCOPE

dB

RV402 hf

Proj. 2

Status

 

 

+10

 

 

 

TP503 GND

+5

INTO

✓

FOCUS

0

REPEAT

12 AND 13

–5

 

 

OUT OF

FOCUS X

–10

.05

 

.1

 

.2

 

.4

 

.8

 

1.6

 

3.15

 

6.3

 

12.5

 

kHz

15

dB +10

+5

 

✓

 

 

 

 

 

 

 

 

0

Cat. No.

 

 

 

 

 

 

 

 

 

240A

 

 

 

 

 

 

 

 

 

–5

 

 

 

 

 

 

 

 

 

 

–10

 

.05

.1

.2

.4

.8

1.6

3.15

6.3

12.5

kHz

Proj. 1

 

 

 

 

 

 

 

 

 

 

GAIN

 

 

 

 

 

 

 

 

 

 

Lt

 

 

 

 

 

 

 

 

 

dB

hf

 

 

 

 

 

 

 

 

 

+10

GAIN

 

 

 

 

 

 

 

 

 

 

Rt

 

 

 

 

 

 

 

 

 

 

hf

 

 

 

 

 

 

 

 

 

 

Lt tp

 

 

 

 

 

 

 

 

 

+5

 

 

 

 

 

 

 

 

 

 

 

Lt

X

 

 

 

 

 

 

 

 

signal

 

 

 

 

 

 

 

 

0

 

 

 

 

 

 

 

 

 

present

 

 

 

 

 

 

 

 

 

 

Rt

 

 

 

 

 

 

 

 

 

Rt

tp

 

 

 

 

 

 

 

 

–5

 

 

 

 

 

 

 

 

 

GAIN

 

 

 

 

 

 

 

 

 

Lt

hf

 

 

 

 

 

 

 

 

–10

 

 

 

 

 

 

 

 

 

 

GAIN

.05

.1

.2

.4

.8

1.6

3.15

6.3

12.5 kHz

 

 

 

 

 

 

 

 

 

Rt

hf

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Proj. 2

 

 

 

 

 

 

 

 

dB

gnd

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

+10

 

 

 

 

 

 

 

 

 

 

+5

X0

–5

–10

.05

 

.1

 

.2

 

.4

 

.8

 

1.6

 

3.15

 

6.3

 

12.5

 

kHz

4-17

A-Chain Alignment Procedures

b. Optical Preamplifier Adjustments

Notes

Disconnect the RTA from the left test point and connect it to the right test point TP502 R. Then repeat Steps 12 and 13. NOTE: The azimuth and high frequency response must be the same at both the left and right test points. If results are not similar, it may be necessary to remove the lens and check for oil or contamination or a degraded slit. Replace the lens, if necessary. Do not proceed to the next step until the outputs at both the left and right test points are similar.

Appendix B shows the effects of slit geometry on frequency response.

The test in this step is performed both at the right and left channel test points of the Cat. No. 240A card.

The frequency response must be within 1 dB to at least 12 kHz. Adjust the L hf and R hf potentiometers on the Cat. No. 240A card for the most extended high frequency response without “peaking.” If these adjustments do not improve the frequency response, the problem may be a degraded slit or damage to the lens.

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Page 34 Page 36
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 Channel Decoder Slot Card Function Cat. NoTwo-channel Noise Reduction ModuleContains 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 Msec Setting Adjustment of Surround DelayThumbwheel Switch 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 +15M Cat. No +24V +15V15V +12B Appendix a Checking Phasing of Speakers Appendix B Effect of Changes in Slit Height on Slit Losses Cat. No a Circuit Description Appendix C CP65M Mono InstructionsOperation Schematic Cat. No a Terminal Block TB3 Appendix D Backplane Connections ListConnector J18
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