Disc Players

Métronome's General Manager, Jean Marie Clauzel, suggested that the 'Sharp roll-off' option in AK's bank of six filter algorithms is the default for the AQWO. While these various filters trade distortion in the time domain [see impulses, inset Graph] for greater/lesser aliasing and a modified treble response, in practice there's a bigger difference in frequency response 'shape' between the AQWO's standard solid-state output [black trace] and its triode tube option [red trace].

A close look inside the AQWO reveals the tube stage is transformer-coupled and this influences not only its low frequency distortion but also its bass response of –2.7dB/20Hz and ultrasonic peak of +1.5dB/32kHz followed by a steep roll-off of –6dB/48kHz to –27dB/90kHz (and steeper still at –21dB/60kHz to –50dB/100kHz with SACD). The standard output [black trace] offers a 'sweeter' treble with a gentler overall roll-off, reaching –2.2dB/20kHz (–3dB for SACD), –6dB/42kHz (–10dB, SACD) and –13dB/90kHz (and –35dB/100kHz for SACD). The inset Graph also reveals that Métronome's tube option is phase-inverting – adding yet another 'hidden' ingredient to the subjective sound quality mix. PM