Pre/Power Amplifiers

A notable feature here is the 'YBA' detailing in the hefty heatsink fins either side of the amp – a neat touch, setting the styling apart. The other major contributor to its mass is the large transformer, which plays a major part in the output, a claimed 200W/8ohm [see PM's Lab Report].

Like the PRE550A, the power amp sits on a trio of feet (two compliant, plus one metal for 'mechanical grounding'), ensuring it sits stably on a shelf. In case you were wondering – as I was, having set the two up before consulting the manual – the power switches are hidden under the units, to the left of the fascia.

The AMP650A offers two sets of speaker outputs per channel, shrouded in removable red and black plastic covers, the upper pair of each coupled via an inductor, the lower direct. Yves-Bernard favours the upper option, which will certainly improve stability with some cable/speaker combinations, and I concurred, finding it delivered a shade more detail with my Chord/QED cables and PMC OB1 and little Neat Iota Alpha speakers [HFN Oct '16].

Sweet And Rich
While the AMP650 may be bridged into a 600W monoblock, you'll not be hankering for extra power any time soon, for the (stereo) AMP650 shows admirable drive and grip, pushing the speakers hard without really betraying much effort. Moreover, when it's partnered with the PRE550A it delivers a sound that's certainly characterful, but entirely entertaining.

The balance here is sweet and rich, but with no shortage of impact and drama when required – the duo can hit hard, whether with music played in through the analogue inputs or fed via its range of digital connections. I hooked it directly to my Mac mini via USB, using Roon as the player and also used my Naim NDS as both an analogue and digital source. I also tinkered with AirPlay music from my computer, but quickly dismissed it as the least satisfactory way to deliver music to these YBAs.

The somewhat anonymous AirPlay sound aside, the YBA pairing impressed with its combination of smoothness and slam, powering out the drums on Japan's 'Visions Of China', from the Exorcising Ghosts compilation [Virgin VGDCD 3510] and evoking the melancholia of 'Night Porter' with a fine combination of ambience and instrumental focus. The sound is full andwarm, yet with high levels of detail and no blurring or overt smoothing of the treble to spoil things. It's worth noting that, if you should find yourself only using the analogue inputs, switching off the digital section brings a worthwhile, if relatively subtle, gain in clarity.

Layers Laid Bare
With the infectious early '90s Brit-house of M People's Elegant Slumming set [Deconstruction 74321 16678 2] the AMP650 lays down the rhythms with total conviction, while also allowing Heather Small's vocal's to soar out of the mix. Bringing things bang up to date with Moby's soulful Everything Was Beautiful, And Nothing Hurt [Little Idiot IDIOT 60CD] shows the pairing's ability to reveal the layers of dense electronica in a recording.

This is one complex set, but the YBA pre/power rises to the occasion with an immersive wash of sound in which every element is clearly apparent. The bass has admirable conviction, whether with the pulsing rhythms of 'Like A Motherless Child' or the great sweep of 'This Wild Darkness', with its near-choral backing. The French amplifiers – or should that be Sino-French? – draw you into the music with their generous, captivating sound, being both supremely easy to enjoy and entirely rewarding.

Strip things down to trio jazz from the Espen Eriksen Trio, with their You Had Me At Goodbye album [Rune Grammofon RCD 2096], and the delicate touch here is much in evidence on a track such as 'In The Woods', where each note of Eriksen's piano shines radiantly, decaying into the acoustic as the next rolls over it, while the understated bass and drums are persuasively placed in a crisply resolved soundstage. That blend of warmth and clarity does a fine job of creating the impression of a very real and palpable performance in the listening room.

This ability is maintained even with large-scale orchestral and/or choral works, where the weight of the PRE550A/AMP650 combines with that smooth but never saccharine top-end to deliver real impact. The glorious recent Dunedin Consort recording of Monteverdi's 1610 Vespers [Linn Records CKD 569; 192kHz/24-bit FLAC] manages to combine a striking sound, packed with ambience and atmosphere, with a beautifully intimate communication with the music, and that's just what this YBA pairing delivers. Passion by name, and passionate by nature!

Hi-Fi News Verdict
High-end sound with a dose of chic and élan – that's this YBA pre/power in a nutshell. Some might argue with the preference for AirPlay, or the limited hi-res range on offer, but the sound is never less than convincing, combining warmth and generosity with finely-judged detail and ambience. The pre has all the flexibility most will need, while the power amp's grip and dynamics make it a fine partner.