Pre/Power Amplifiers

This new Cadenza C41 is a clear evolution over the older C31 [HFN Sep ’12] despite there being very little uplift in price (about £1000) in some 12 years. The C31 was limited to 96kHz playback, the C41 to 192kHz/DSD64, just as the former employed a Crystal CS4398 DAC and the latter an ES9038PRO. Some core philosophies are retained, albeit improved, including the balanced analogue output stage which, at maximum volume (‘70’ on the display), still delivers 4.0V from a 97ohm source impedance. In the C41, however, the C31’s 113dB A-wtd S/N ratio is improved to a very wide 115.8dB regardless of digital input. Low distortion was another hallmark of the C31 and it’s lower still through the C41 – a feature of both MBL’s own core DSP as it is the ESS DAC – at 0.00005-0.00035% (20Hz-20kHz, re. 0dBFs). Distortion is lowest over the top 10dB of the C41’s range [see Graph 1], falling to a minimum of 0.00003-0.0002% (also 20Hz-20kHz). Low-level resolution is true to ±0.2dB over a full 110dB dynamic range and digital jitter is almost fully suppressed at <8psec via all digital inputs over all 44.1-192kHz/24-bit rates.

The response, meanwhile, is modified by MBL’s own slow roll-off minimum phase digital filter and, of course, the incoming sample rate, resulting in slightly early treble roll-offs of –3.55dB/20kHz and –1.25dB/20kHz with 44.1kHz and 48kHz files, respectively, before reaching out to –6.2dB/45kHz and –10.9dB/90kHz with 96kHz and 192kHz audio media [Graph 2]. MBL’s filter operates in place of one or more of the seven digital filters bundled into the ESS DAC and trades greatly reduced post-ringing (and zero pre- or acausal ringing) for a relatively limited stopband rejection of just 19dB. For an independent analysis of MBL’s ‘True Peak Technology’ [see boxout]. PM

Hi-Fi News Measured Specifications:

Maximum output level / Impedance	3.99Vrms / 97ohm (XLR)
A-wtd S/N ratio (USB/Coax; re. 0dBFs)	115.8dB / 115.8dB
Distortion (1kHz, 0dBFs/–30dBFs)	0.00005% / 0.00025%
Distortion & Noise (20kHz, 0dBFs/–30dBFs)	0.00035% / 0.0005%
Freq. resp. (20Hz-20kHz/45kHz/90kHz)	+0.0 to –1.3dB/–6.2dB/–11dB
Digital jitter (48kHz / 96kHz / 192kHz)	5psec / 6psec / 8psec
Resolution (1kHz @ –100dBFs/–110dBFs)	±0.1dB / ±0.2dB
Power consumption	22W (1W standby)
Dimensions (WHD) / Weight	450x145x445mm / 15.5kg