Dolby Laboratories DA20 User Manual - Page 5

Browse online or download pdf User Manual for Computer Hardware Dolby Laboratories DA20. Dolby Laboratories DA20 18 pages. Digital film sound processor

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1. About the Dolby Da20 and the Dolby Stereo Digital Format

• Adjustable time delay for mounting the Cat. No.700 Digital Soundhead up to 135

frames in advance of the analog soundhead.

• Adjustable surround delay to match theater size.

• Simple interface to the Dolby Cinema Processors.

• Comprehensive Cinema Processor status display.

• Automatic switching to analog soundtrack in the event of damaged or missing digital

data.

The DA20 includes interface cables to mate with the required Cinema Processor type.

Dolby Digital prints have conventional SR analog and digital tracks which enables low-

cost 35mm optical prints to deliver the volume range, fidelity and discreteness previously

associated only with 70mm releases. The Dolby Digital format utilizes an innovative

digital encode/decode process, Dolby AC-3. The process translates five full range (20-20

kHz) channels plus a subwoofer audio channel and auxiliary data channel into a series of

data blocks, printed between the perforations of standard 35mm film. On playback, the

data blocks are scanned by an optical pickup head, and transformed back into full

professional quality digital audio. Release prints in the Dolby Digital format also contain

standard SR encoded Dolby Stereo analog tracks, resulting in single inventory prints and

unprecedented quality and reliability in film audio presentation.

This manual describes the operation of the DA20 when equipped with a Cat. No. 611A

Cinema Processor Interface card. The Cat. No. 611A has features that were not available

on the original Cat. No. 611. In particular, the automatic selection of Format 10 (Dolby

Digital), Format 05 assertions after a power failure, and other improvements are now

incorporated. Thus, the manual sections that describe the operation of auto digital and

power failure format assertion are not applicable to those units which are equipped with

the original Cat. No. 611 card.

To determine if a Cat. No. 611A is installed in your unit, look through the CP Status

opening on the DA20 front panel. If your unit is equipped with a Cat. No. 611A, you will

see "CAT. NO. 611A" printed on the PC board just inside the window immediately below

the "Analog" LED. Behind the text you will also see a cross hatched pattern printed on

the board. These two markings indicate that your unit is equipped with a Cat. No. 611A.

Your installer can provide details.

If your unit is not equipped with a Cat. No. 611A, the switch positions for Auto Digital

Disabled modes are not available and the CP Type is selected using positions 1 through 3

depending on which cinema processor is attached. See manual Section 1.4

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