Integrated Amplifiers

Rated at 125W/8ohm but delivering 2x148W and 2x245W into 8/4ohm loads, respectively, the No5805 has sufficient headroom to accommodate bursts of 174W and 328W into 8/4ohm loads under dynamic conditions (10msec, <1% THD). This is limited to 305W and 172W into lower 2/1ohm loads [see Graph 1, below]. Distortion increases slightly with frequency from 0.014-0.038% (20Hz-20kHz) but remains very consistent with power output over the rated 125W range. The response is very extended with –1dB points at 1Hz-49kHz (–3.5dB/100kHz) but noise – even if this is an innocuous 'white noise' – is a little below average, leading to an A-wtd S/N ratio of 78dB (re. 0dBW).

ML's 'Precision-Link II' DAC stage confers a near-total suppression of correlated jitter (<5psec across all sample rates), a low 0.0003-0.0014% distortion (20Hz-20kHz re. 0dBFs) but modest 101dB A-wtd S/N (re. 2V preamp output). Three of the seven digital filters are steep roll-off linear phase types (with pre and post-event ripples) including Brickwall, Fast Linear [green traces, Graph 2] and Apodising, offering stopband rejections of 99dB, 83dB and 92dB, and very flat responses (typ. ±0.02dB/40kHz with 96kHz files). 'Slow Linear' shows only two pre/post ripples at the expense of a poorer 14dB stopband rejection and gentler treble (–3.4dB/20kHz with 48kHz files). The two minimum phase filters – Fast [red traces, Graph 2] and Slow – offer greater and lesser post-event ringing, respectively. A hybrid filter blends both characteristics: reduced time domain distortion and excellent 99dB stopband rejection at the expense of a 0.1dB ripple in the passband [black traces, Graph 2]. PM