Sony STR-DA1000ES ES Receivers Technical Background - Page 14

Two-Stage Pulse Power Supply The power supply is always a critical component of amplifier sound quality. And this continues to be true of digital amplifiers. That's why Sony designed the S-Master Pro amplifiers with incredibly stable power supplies. The STR-DA2000ES, DA3000ES and DA5000ES take advantage of Sony's twostage pulse power supply. At 200 watts per channel across seven channels (20-20,000 Hz, 8 ohms, 0.15% THD), the STR-DA9000ES required something even more robust, an absolutely massive Toroidal power supply, discussed later in this paper. Simply stated, a receiver's power supply should output stable voltage no matter what the music is doing. Even during the most demanding musical peaks, the power supply output should be smooth and steady. 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