Dolby Laboratories CP65 manual Auto Freq

Page 64

5-50

B-Chain Alignment Procedures

h. Adjustment of Non-sync Gain

Step			Action	Indication
No.
5			Cat. No.
5			441
		signal
		present
			tp
Subwoofer			on
			cut	Dolby
	auto		freq
		off	Q
		off

n-sync		opt gain
surr		mag/dig
gain		gain
		treble
Surround			cut
	mid		freq
			Q
Left			Q
Left			bass
			bass
			tp
		treble
Surround			cut
	mid		freq
			Q
Right			bass
Right			gain
			gain
			gnd
		signal
		present
		Cat. No.
			242
mono eq
mono
gain
non-syncL
		R
		L		Dolby
		L
signal		C
present R
		Ls
	gnd
		L
test		C
test
points		R
		Ls
		L
gain		C
gain		R
		R
		Ls
6			Cat. No.
			441
		signal
		present
			tp
Subwoofer			on
			cut	Dolby
	auto		freq
	off		Q
	off

n-sync	opt gain
surr	mag/dig
gain	gain
Surround		treble
			cut
	mid		freq
			Q
Left			Q
Left		bass
		bass
			tp
		treble
Surround			cut
	mid		freq
			Q
Right		bass
Right		gain
		gain
			gnd
		signal
		present

5-51

B-Chain Alignment Procedures

h. Adjustment of Non-sync Gain

Notes

Turn the Non sync surround gain on the Cat. No. 441 fully counterclockwise.

Play a cassette or CD on the non-sync device and adjust the non-sync L (left) and non- sync R (right) controls on the Cat. No. 242 B-Chain card for the desired level in the theatre. If possible, select a recording that has a natural ambience such as an orchestral work.

Adjust the Non sync surround gain control on the Cat. No. 441(if fitted) for the desired surround level in the auditorium. This control is not present on a Cat. No. 241.

Image 64

Contents Model CP65 Cinema Processor Dolby Laboratories Inc Headquarters Table of Contents Section Reference Block Diagrams Introduction Page Section Equipment Required Smpte Buzz Track Stereo Optical Surround Level Cat. No Jiffy Test Film Cat. No 2 Listen . . . Film Cat. NoSection Initial SET-UP and Installation Voltage Acceptable Setting Voltage Range Fuse Type Next, check the jumpers in the following locations Cat. No , Power Supply Module Cat. No , B-Chain CardCat. No , Control Logic Card J2 NON-SYNCCP65 Backplane Standard CP65 or CP65ACP65-300 High Low Subwoofer subwoofer Output output These Modules are Necessary for Bypass Operation Slot Card Function Cat. No Two-channel NoiseReduction Module Channel DecoderContains a semi-regulated power supply with Voltage Setting Fuse Type InternationalIEC Notices HUM Problems Room lighting dimmer controls SCR-TYPEPage Section AN Overview of the Alignment Procedure Aligning the B-ChainPage Page Section Chain Alignment Preliminary Procedures Action IndicationLamp Voltage Optical Preamplifier Adjustments Chain Alignment Procedures Optical Preamplifier Adjustments 222 CAT. no Test Film Oscilloscope Traces Repeat CAT no Repeat 1 →Magnetic Preamplifier Adjustments Magnetic Alignment 100mV Section Chain Alignment Setting Room Equalization BypassLoudspeakers and Crossovers Amplifiers GeneralChain Alignment Procedures OffRepeat ActionChain Alignment Procedures Setting Room Equalization Do not adjust Paul Setting Room Equalization b. Adjusting L,C,R Gain 14 → 21 R 14 →Setting Mono Gain 79 dBCChain Alignment Procedures Subwoofer Alignment Cat. No 90 dBC 85 dBCFrom Step NoSelect format 04 Dolby Stereo A-Type Same AS 441Surround Equalization Alignment Cat. No Surround Equalization Alignment Cat. No Notes Cat. No 441Desired 88 dBC Bypass Thumbwheel Switch Adjustment of Surround DelayMsec Setting Chain Alignment Procedures Adjustment of Bypass Gain Xx dBCFrom Xx dBC -3 dB Yy dBCAdjustment of Non-sync Gain Press the format 60 non sync switchAuto Freq Adjustment of Mono Gain and Equalization Notes Repeat page 5-20 StepChain Alignment Procedures Final Checks Press the format 04 Dolby Stereo A-type switchSection 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 15V +12B Cat. No +24V +15V+15M Appendix a Checking Phasing of Speakers Appendix B Effect of Changes in Slit Height on Slit Losses Operation Appendix C CP65M Mono InstructionsCat. No a Circuit Description Schematic Cat. No a Appendix D Backplane Connections List Terminal Block TB3Connector J18