Disc Players

The little green daughter board is a real blast from the past – a combination of Cirrus Logic's (née Crystal's) CS8420 asynchronous upsampler with the once-ubiquitous 192kHz-compatible CS4398 DAC. The latter is still going strong after some 17 years on the books while the former was obsoleted in 2019... Nevertheless the pair put up a very strong performance, supplemented in no short measure by Electrocompaniet's discrete and fully balanced output buffer that delivers a maximum 4.38V output from a moderate 139ohm source impedance. White noise is low too, and despite some spurious/idle tones at 710Hz, 2.03kHz and 3.36kHz, the player still delivers a robust 111dB A-wtd S/N ratio (113dB would be achievable). Low-level linearity is excellent too with errors of just ±0.5dB over a full 110dB dynamic range suggesting a resolution of some 18-bits for dithered 16-bit CD data.

Cirrus Logic's high-order linear-phase digital filter has been selected in this implementation, endowing the EMC 1 MKV with a ruler-flat response (just +0.00/–0.02dB from 20Hz-20kHz!) and a near-total 112dB suppression of stopband distortions. This is traded, as always, for more significant pre/post echoes in the time domain. Conventional harmonic distortion falls to a minimum of ~0.00035% at –10dBFs, increasing slightly at the player's peak output, but the close matching of this distortion regardless of frequency [see black/blue traces, Graph 1] is encouraging from a subjective standpoint. Digital jitter is low too at ~135psec [see Graph 2, below], showing a mere 20psec of peaks unrelated to the baseline inherent with the 16-bit J-test [mkrs 3, 5, 8, 11, 15, 20, 22 and 24]. Finally, the 'dual mono' analogue layout yields a fine >110dB channel separation. PM