Disc Players

McIntosh Labs offers a surprisingly modest specification for its SACD-playing/USB DAC combination player which is at least partially inspired by the larger MCD600. The combination of Crystal's CS8421 sample-rate converter with tried-and-tested ES9016S DAC from ESS Technology limits all LPCM streams to 192kHz although the frequency response peaks upwards to +0.3dB/20kHz with CD/48kHz inputs and +0.6dB/45kHz with 96kHz media. The higher-rate 192kHz files roll off to –8.1dB/90kHz while SACD/DSD64 media reach out to –0.4dB/40kHz, –7.2dB/60kHz, –19dB/80kHz and –31dB/100kHz. Incidentally, the digital filter for LPCM data is a steep roll-off linear phase type offering a superb >115dB stopband rejection with CD. The resolvable range, however, is limited to –96dBFs with CD data and –104dBFs with 24-bit LPCM feeds as inputs are truncated below these levels. The 'step' is clearly visible on the distortion versus digital signal level traces [Graph 1] which also illustrate the unexceptional – though acceptable and usefully uniform – circa-0.01% THD over the top 40dB of the player's dynamic range. Interestingly, SACD/DSD64 is not truncated and offers a far superior low-level resolution of ±0.2dB down to –120dBFs.

The top-line figures for the MCD85 are as expected – maximum (balanced) output is 4V from a 100ohm source impedance, increasing to 333ohm/20Hz via the capacitor-coupled analogue stage, while the A-wtd S/N ratio is a fine 114dB with 24-bit LPCM and 109dB with SACD/DSD64 sources. Correlated jitter is low at 115psec via USB and coaxial inputs and very low at 30psec with SACD, although a broad uncorrelated noise is also evident [see Graph 2, below]. PM