Advertisement
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
CD
24 bit/8 fs
16 bit/1 fs
8x
Oversampling
Noise
digital filter
shaper
SACD
1 bit/64 fs
DSD
filter
1 bit/64 fs
1 bit/64 fs
Multi level
D/A converter
Page 31
Advertisement
