MARANTZ PS17
Service Manual

12. TECHNICAL DESCRIPTION
This product has two DSP ICs, one is for Dolby Digital (AC-3) decoding or DTS (Digital Theater System) decoding, another is for Dolby H.P. processing. Multi channel sound is reproduced by connecting with DVD player or LD player. Also Dolby Pro Logic decode is available to analog audio and PCM digital audio. Additionally, 96kHz PCM stereo audio playback is possible. Decoding circuit is consist of 13 ICs (DIR, tree DSP, ADC, �ve DAC, two data separator and CPU). DOLBY DIGITAL (AC-3) Dolby Digital delivers six totally separate (discrete) channels of sound. Like Dolby Surround Pro Logic, it includes Left, Center and Right channels across the front of the room. Dolby Surround Pro Logic provides a single limited-bandwidth (100 Hz to 7,000 Hz) surround channel which is typically played back in the home through two channels of ampli�cation and two speakers. In comparison, Dolby Digital provides separate (discrete) left surround and right surround channels, for more precise localization of sounds and a more convincing, realistic ambience. And, with Dolby Digital, all �ve main channels are full range (3 Hz to 20,000 Hz). A subwoofer could be added to each channel, if desired. The sixth channel, the Low Frequency Effects Channel, will, at times, contain additional bass information to maximize the impact of scenes such as explosions, crashes, etc. Because this channel has only a limited frequency response (3 Hz to 120 Hz), it is sometimes referred to as the .1 channel. When added to the 5 full range channels, the Dolby Digital system is sometimes referred to as having 5.1 channels. DTS An amazing new technology for surround-sound entertainment, DTS Digital Surround is an encode/decode system that delivers six channels (5.1) of master-quality, 20-bit audio. In the encoding process, the DTS algorithm encrypts six channels of 20-bit digital audio information in the space previously allotted for only two channels of 16-bit linear PCM. Then during playback, the DTS decoder reconstructs the original six channels of 20-bit digital audio. Each of these six channels is audibly superior to the 16-bit linear PCM audio found on conventional compact discs. SRS The playback mode is selected as follows depending on the input signals and speakers used.

· When the setting calls for the surround speakers to be used:
UltraSurround processing is added when multi-channel signals are input. This causes the sound to be reproduced in a wide sound �eld with improved links between the channels. Circle Surround playback is performed when 2-channel signals are input. In this case, either music mode or cinema mode can be selected. CS CINEMA: This is suited to movie playback. Conventional movies recorded in surround sound will also be played back as 5.1-channel sound. CS MUSIC: This is suited to music playback. Two-channel music sources are converted into 5.1-channel sound for playback.

· When the selling does not call for the surround speakers to be used:
Using only the front speakers virtual surround sound playback results to give the impression that surround speakers are present. Virtual surround sound playback using TruSurround is performed when multi-channel sound is input. CS Virtual surround sound playback is performed when 2-channel signals are input. In this case, the Circle Surround effect can be enjoyed by the front speakers alone. Note: The effect will differ depending on the playback source and viewing/listening position. The sound of some sources may be played back unnaturally. Playback is not initiated for 96 kHz PCM input signals. 6.1 Surround This can be used when back surround speakers are used. Unique matrix processing is performed for the surround channels among the 5.1-channel signals to generate back surround channels. This further enhances the sound of the source subjected to Surround EX or DTS-ES processing.

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