User manual SONY ST-RGX49ES

[. . . ] The world's first Dolby® Surround decoder to operate in the digital domain (SDP-505ES, 1986). The world's first all-digital preamplifier (TA-E1000ESD, 1989). 24-bit Dolby Digital® decoding (SDP-EP9ES, 1997). Digital Cinema SoundTM processing (STR-DA90ESG, 1997). [. . . ] Sony's Two-Stage Pulse Power Supply does a remarkable job in achieving exactly this result. The first stage is a switching or "pulse" power supply of high performance. The second stage is an analog constant voltage power supply, for an even higher degree of stability. The cumulative effect is remarkably stable performance, even when a rock band is playing all-out, or when a movie sound track includes car crashes and explosions. On the left, these fluctuations, at the input of the Pulse Power Supply, are unacceptable for high fidelity audio reproduction. In the center, the output of the Pulse Power Supply is substantially better, but still not up to the standards of Sony ES. At right, after the analog constant voltage power supply, the power is ready for true high-resolution audio reproduction. The pulse power supply of the STR-DA5000ES is remarkably compact and efficient. ES Receivers V3. 0 Page 14 S-Master Pro Benefits No crossover distortion Conventional power amplifiers use separate transistors to reproduce the upper and lower halves of the waveform. Crossover distortion occurs when one power transistor switches off and the other switches on as the audio waveform "crosses over" the zero point between negative and positive. This distortion is particularly bothersome because it remains constant as the signal gets softer. This makes the distortion more audible during the quiet passages of music or movies. Conventional amplifiers combat crossover distortion with the output transistor bias current of Class A/B designs. Ironically, this bias current generates even more heat. And instead of a complex, circuitous signal flow, driven by the need to hold the output transistors away at the periphery, the S-Master Pro signal flow can be refreshingly simple and straight. ES Receivers V3. 0 Page 17 The internal layout of the STR-DA4ES analog amplifier is driven by the issue of heat dissipation. The entire design is dominated by the output transistor heat sink fins. In dramatic contrast, the power amplifier of the STR-DA2000ES is amazingly compact. The S-Master LSIs (1) convert the signal to a Pulse Length Modulation 1-bit stream. Thanks to low heat generation, the power output transistor heat sinks (2) can be quite small. Finally, the Low-Pass Filters (3) convert the power pulses to audio for the speaker terminals at the top of the picture. ES Receivers V3. 0 Page 18 In the STR-DA4ES (top), the signal flows from the center, to the sides and back to the center again for point-to-point wiring to the speaker output terminals. On the STRDA2000ES (bottom), the signal flows in one direction only. Superb open-loop performance Conventional amplifiers typically generate substantial distortion in "openloop" mode. That's why analog amps use Negative Feedback (NFB). NFB constantly compares the output with the input, identifying open-loop distortion and applying an equal-but-opposite correction signal at the input. NFB is a powerful tool for limiting distortion, and NFB explains the low distortion specifications common today. However, NFB exposes the signal to Transient Intermodulation Distortion and other dynamic problems. In contrast, the Sony S-Master Pro amplifier achieves excellent fidelity without any negative feedback at all! [. . . ] Using a proprietary Sony Large Scale Integrated circuit (LSI). 6. 0-channel Digital Cinema Sound concert hall modes (all models). For the Amsterdam Concertgebouw and the Vienna Musikvereinsaal. 7. 1-channel Cinema Studio EX modes (all models). [. . . ]