Sansui RZ 3700AV 5700AV 7700AV Service Manual

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I] SANSUI AV RECEIVER

RZ-3700AV/RZ-5700AV/RZ7700AV

SERVIC Manual-

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CONTENTS

Specifications

. Adiustment

. Block Diagrams

. Schematic Diagrams
. Wiring Diagram

. PCB Diagrams

. Mechanical Parts List

. Electrical Parts List

*Design and specifications are subject to change without notice for improvements
*CAUSION : Parts identified the SAFETY symbol( A ) on the schematic diagram and

the parts list are critical for safety.

Use only replacement parts that have critical characteristics recommended

by the manufacturer.

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DOLBY DIGITAL SURROUND

Dolby Laboratories spearheaded home theater with the introduction of Dolby Surround, and then defined it with the follow-up
format Dolby Pro-Logic Surround. They have continued the evolution of home theater with the introduction of Dolby Digital
Pro-Logic, a Multi-Channel Digital delivery system. Just as Dolby Surround found its beginnings in the cinema, so does Dolby
Digital. This advanced multi-channel digital sound, although originally conceived for and later chosen for HDTV, made it prec-
tical to implement in the cinema because it enabled the film to retain the analog soundtrack. With backwards compatibility a
priority so the film could be played in any cinema, it was decided to place the new digital optical track between the sprocket
holes, which was a key factor in defining its maximum practical bit rate (see illustration).

5.1 , Channel
Digital Soundtrack 4rChannel Analog
Soundtrack (Matrixed)

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DEEMED

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ENCODING

AC-3 IN THE CINEMA

In 1992 Dolby Surround Digital, the film sound format with Dolby Digital as its keystone, made its debut in the cinema. In less
than three years, more than 300 feature films had been released in this new format, and nearly 1,500 cinemas had been
equipped for playback of the digital soundtrack. Furthermore, Dolby Digital can now be brought to the consumers home today
via the LaserDisc.

Traditional Pulse Code Modulation (PCM), which is utilized on compact discs and LD's 4-channel matrixed digital audio
tracks, uses a 16-bit word to describe" the sampled point in the original analog wave. By sampling this analog wave 44,100
times per second for each channel, the system will yield a dynamic range of 96 dB from the loudest sound to the noise floor.
However, this process creates an immense amount of data which is too large for multi-channel systems. Thus, a form of data
reduction must be employed to reduce the total amount of information without serious degradation of the sound quality -
hence the introduction of Dolby Digital.

The premise of Dolby Digital is simple, it reproduces the full bit resolution (16-bit) when a lower resolution will not result in the
same sound quality. However, when a lower resolution is acceptable, it will utilize this lower resolution opting instead for psy-
choacoustical theories and digital noise filtering technologies to help insure acceptable sound quality.