Weiss DAC501 USB/network DAC Lab Report

So these measurements might be compared with those of competing DACs, Weiss's various DSP plug-ins were defeated and the 'Main Level' set at '0dB'. The maximum 6.67V, phase-positive, balanced analogue output is delivered via a very uniform 45ohm source impedance and, courtesy of the output stage's exceptionally low noise, boasts a huge 119.4dB A-wtd S/N ratio. Low-level linearity also benefits, with the DAC501 holding true within ±0.04dB over a 110dB range. Its low distortion is not only on a par with the very best – including Chord's DAVE and Hegel's HD30 [HFN Apr '16 and Jan '16] – but is also impressively uniform with both frequency and digital level. For example, distortion – mainly 2nd-5th harmonic – is within 0.0003% through bass and midrange, falling as low as 0.0001% over the top 30dB of its dynamic range, while achieving <0.0004% under the same conditions at 20kHz [see Graph 1].


Distortion versus 48kHz/24-bit digital signal level over a 120dB dynamic range (via S/PDIF and USB at 1kHz, black; 20kHz, blue)


High resolution 48kHz/24-bit jitter spectrum (x10 zoom, grey infill, showing uncorrelated jitter)

The default digital filter is a medium/steep roll-off, linear phase type with equal pre/post-event ringing. This 'time domain' distortion is traded against a full >90dB stopband rejection, ensuring no ultrasonic aliasing artefacts make their way into your amplifier while still extending the response out to –0.3dB/20kHz, –2.3dB/45kHz and –7.0dB/90kHz with CD/48kHz, 96kHz and 192kHz digital sources, respectively. There's a note buried in Weiss's technical white paper alluding to the DAC50x's use of an asymmetric/off-centre re-clocking frequency (195kHz) – a technique also employed by Hegel. In this instance the suppression of correlated jitter is also state-of-the-art at <10psec over all CD-192kHz sample rates, although a trace of some noise-like/uncorrelated jitter remains [see Graph 2]. PM

Maximum output level / Impedance: 6.66Vrms / 45ohm (XLR out)
A-wtd S/N ratio (S/PDIF / USB): 119.4dB / 119.3dB
Distortion (1kHz, 0dBFs/–30dBFs): 0.0003% / 0.0003%
Distortion & Noise (20kHz, 0dBFs/–30dBFs): 0.0004% / 0.0004%
Freq. resp. (20Hz-20kHz/45kHz/90kHz): +0.0 to –0.3dB/–2.3dB/–7.0dB
Digital jitter (48kHz/96kHz / USB /net): <10psec / <10psec / <10psec
Resolution @ –100dB/–120dB (S/PDIF): ±0.0dB / ±0.8dB
Power consumption: 14W (1W standby)
Dimensions (WHD) / Weight: 188x66x300mm / 6kg
Price: £720

Weiss Engineering Ltd
Supplied by: Padood Ltd, Cambridge, UK
01223 653199