Disc Players

User-selectable digital filters are not uncommon, as we saw in Oppo’s UDP-205 [HFN Jul ’17] and Matrix Audio’s X-Sabre Pro [HFN Nov ’17], and typically include sharp and slow roll-off versions of linear and minimum phase filters. For the Vivaldi One, dCS has included six filters for CD, four for 48kHz-96kHz media and six for 176.4kHz+ media, the majority being linear phase types that trade ringing in the time domain against stopband rejection. While the CD filters all offer a perfectly flat 20Hz-20kHz response (±0.05dB), only Filter 5 is a minimum phase type, similar to Filter 6 for 192kHz data [blue impulse and response on inset Graph]. dCS has its own ‘NOS’ Gaussian filter that it (very sensibly) reserves for high sample rate inputs only [Filter 5 for 192kHz inputs, green traces]. Used with CD/48kHz inputs this type of filter would produce a marked loss in HF response and even with 192kHz files is –0.4dB/10kHz, –1.6dB/20kHz and –6.5dB/40kHz. Filters 1-4 are all linear phase for all sample rates [black, red, cyan and orange]. The DSD filters 1-3 are flat to 20kHz: DSD Filters 1 and 2 reaching 100kHz at –8.5dB and –21dB, respectively, Filter 3 rolling off to –3dB/60kHz and –23dB/80kHz while DSD Filter 4 is –0.7dB/20kHz, –6dB/30kHz and drops steeply at 40kHz. PM