CD | | | 24 bit/8 fs |
16 bit/1 fs | 8x | | 1 bit/64 fs |
| |
| Oversampling |
| Noise |
| digital | filter |
| shaper |
| | |
SACD | | | Multi level |
| | D/A converter |
1 bit/64 fs | | | |
| DSD | |
| filter | |
| | | 1 bit/64 fs |
Sony's Super Audio D/A Converter (SA DAC) does an equally superb job on Compact Disc signals (top) and SA-CD signals (bottom).
The converter consists of a single integrated circuit that contains four significant circuits:
1.8x oversampling digital filter for CD. Ensures accurate phase linearity and low noise.
2.Noise shaper for CD to further suppress audible noise. The noise shaper also puts out a 1-bit signal at 64 times the CD sampling frequency (1-bit/64 fs). Sixty-four times 44.1 kHz equals 2.8224 MHz, the same sampling frequency as Super Audio CD. In this way, the SA DAC presents both CD and SA-CD signals to the final converter stage in the identical 1-bit/64 fs form.
3.DSD® filter for SA-CD,a digital filter that removes unwanted super high frequency noise by computing raw 1-bit digital data. By reducing noise in the digital domain, the DSD filter reduces the burden on analog filters and contributes to the uniformity among channels.
4.Multi-level DAC for both SA-CD and CD is a breakthrough design that combines the best attributes of 1-bit converters and multi-bit converters for sound that is exceptionally transparent, against a background that is phenomenally free from noise.
Sony's multi-level digital-to-analog conversion is a significant step forward in audio technology. To appreciate the advance, it's important to understand three types of digital-to-analog converters: multi-bit, 1-bit and multi-level.
ES DVD Players 2005, Version 4.0 | Page 31 |
