Outboard DACs

Fed a peak level (0dBFs) digital input this latest in a long line of 'DacMagics' offers a full 3.85V, from a ~45ohm source impedance, via its balanced XLR outputs. While this is perfectly standard, the very wide 115dB A-wtd S/N ratio is less so – a figure closer to ~110dB would be more likely from a pair of ES9028Q DACs. In practice this is achieved because the DacMagic 200M mutes its output with digital inputs below –105dBFs, as evidenced by the step visible near the top of the distortion vs. digital level profile [see Graph 1, below]. Time will tell whether this catches out other 'technical' reviews but while the DAC's low-level linearity is good to ±0.3dB over a 100dB range its resolution is necessarily restricted to a little over 17-bits. Otherwise this is textbook stuff offering very low distortion – 0.0001% through bass and midrange at 0dBFs, down to 0.00005% at –10dBFs. Jitter is fabulously low too at ~10psec with all sample rates from 44.1kHz-192kHz.

Three digital filters are offered, called 'Fast', 'Slow' and 'Short Delay' [see Graph 2]. The former is a standard linear phase type offering a moderate 83dB stopband rejection and very flat response (–0.1dB/20kHz, –0.65dB/45kHz and –1.4dB/90kHz with 48kHz, 96kHz and 192kHz media), 'Slow' is a limited-tap linear phase type with significantly reduced ringing in the time domain but a poorer 6dB stopband rejection and a more rolled-off response (–3.0dB/20kHz, –4.0dB/45kHz and –4.7dB/90kHz with 48kHz, 96kHz and 192kHz media). Subjectively, this will be the most distinctive choice, particularly with 44.1/48kHz media. The 'Short Delay' filter is a steep roll-off minimum phase type with extended post-ringing, no pre-ringing and similar stopband and response characteristics to the 'Fast' filter. PM