Sony CDP-X77ES CD player

With Sony's latest flagship single-box player ($1700), we find yet another variant on 1-bit D/A technology—High Density Linear Converter, or HDLC. At the heart of this Pulse Length Modulation (footnote 1) D/A technique is Sony's CXD-2552 Pulse D/A converter (two per channel in complementary mode in the CDP-X77ES). This complex LSI chip incorporates a third-order noise shaper, the PLM converter, and a digital sync circuit receiving its input from the system clock.