Dolby Laboratories CP65 manual Desired

Page 57

5-36

B-Chain Alignment Procedures

e. Surround Equalization Alignment (Cat. No. 441)

Step

Action

Indication

No.

6

Cat. No.

441

dB

signal

+10

present

tp

D I P

Subwoofer

on

cut

+5

auto

freq

Dolby

off

Q

n-sync

opt gain

surr

mag/dig

gain

gain

0

treble

Surround

cut

mid

freq

Q

–5

Left

bass

tp

treble

–10

cut

Surround

.05

.1

.2

.4

.8

1.6

3.15

6.3

12.5

kHz

mid

freq

Q

Right

bass

gain

gnd

signal

present

7

Cat. No.

441

dB

signal

+10

present

tp

Subwoofer

on

cut

+5

auto

freq

off

Q

Dolby

n-sync

opt gain

surr

mag/dig

gain

gain

0

treble

Surround

cut

mid

freq

–5

Left

Q

bass

tp

–10

treble

Surround

cut

.05

.1

.2

.4

.8

1.6

3.15

6.3

12.5

kHz

mid

freq

Q

Right

bass

gain

gnd

signal

present

8

Cat. No.

441

signal

dB

present

tp

+10

Subwoofer

on

cut

auto

freq

+5

off

Q

DESIRED

n-sync

opt gain

Dolby

RESPONSE

surr

mag/dig

gain

gain

treble

0

Surround

cut

mid

freq

Q

–5

Left

bass

tp

–10

treble

cut

.05

.1

.2

.4

.8

1.6

3.15

6.3

12.5

kHz

Surround

mid

freq

Q

Right

bass

gain

gnd

signal

present

9

REPEAT

6 → 8

5-37

B-Chain Alignment Procedures

e.Surround Equalization Alignment (Cat. No. 441) Notes

Turn the freq control so that the notch is located over the peak noted in the previous step.

Adjust the Cut and Q controls for the flattest response in this part of the spectrum.

Adjust the treble control on the Cat. No. 441 card for the best approximation to the desired response shown.

The treble and mid equalizer controls interact. Repeat the adjustments until no further adjustment is required and you have attained the optimum frequency response.

Image 57

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