The Naim SUPERNAIT, released in 2007, was unusual because it contained DAC circuitry and had digital inputs so that users could connect their 21st-century digital sources – computers, media servers and the like – directly to the amplifier.

This marriage of convenience and high performance proved hugely popular, to the extent that Naim has now produced the Son of SUPERNAIT, the less costly design whose development name apparently was the NAIT Speed, but which is now officially called the Naim NAIT XS.

Fitted into a slimline aluminium Series 5 case, the amplifier is powered by a 380VA toroidal transformer, but can be usefully supercharged with a flat-cap, hi-cap or Super-cap external power supply for anyone who wants to extract the maximum amount of performance from this no-frills design. It might look like the familiar NAIT 5i, but under the hood there's a powerplant derived from the SUPERNAIT.

Clever technology

Although the NAIT XS benefits from an optimised, shortened and simplified signal path, this isn't the only performance-enhancing feature it enjoys.

The design is the first to employ Naim's newly developed bayonet PCB mounting technique, which permits the board to 'float', reducing microphonic effects. Furthermore, the heatsink is castellated to provide maximum cooling for reliability, enhanced dynamic performance and to reduce the capacitance effects of a small number of longer PCB tracks.

Naim has been aware of the problems caused by vibration creeping inside its electronics for some time, and the XS includes features specifically designed to reduce it. That's why, for example, the mains switch and IEC socket on the rear panel are also allowed to float and aren't immovably attached to the chassis.

This controlled freedom reduces air- and structure-borne vibration entering the amplifier through the mains cable. Many detailed aspects of the construction of this amplifier might sound far-fetched to a cynic, but each has undergone stringent listening tests to demonstrate its validity and justify its inclusion in the design.

This extends as far as the precise placement and tightness of the cable ties used to dress the minimal cable runs. While that might sound rather like obsessive/compulsive behaviour, if it makes an audible difference where a cable tie is placed, then why not address that situation? Especially when the cumulative effects of these 'insignificant' considerations are audible and beneficial.

Amp connectivity

The amplifier has six line-level analogue inputs, one of which, like Naim's preamps and the SUPERNAIT, outputs power to run an external Naim phono stage, which is a worthwhile facility for those who value the superlative performance that vinyl offers. Conversely, for those who don't, there's an auto-switching 3.5mm stereo-jack socket on the front panel for connecting an iPod or other MP3 player.

The XS also offers a unity gain option and an AV bypass function, whereby it can be used in conjunction with an AV processor in a home cinema system. This is controlled by a rear-panel switch, which for normal use should be set to 'off'.

Be warned: when the bypass mode is selected, the signal connected to the AV input passes straight through the XS at full gain – neither the volume control nor the mute button will have any effect upon it!

Versatile device

The Naim NAIT XS provides preamp-out and poweramp-in sockets that are connected with a linking plug for normal integrated-amplifier operation. It also provides an unfiltered analogue stereo subwoofer output through a pair of RCA phono sockets.

This duplicates the preamplifier output and has no low-pass filtering applied. (Since this is a full-range signal and the output is happy to drive long interconnects, it could conceivably be used as a line-level feed to another power amplifier and speakers to extend the main system's sound into a second room.)

While the XS is obviously going to work well in a system with other Naim components, the model is also designed to be sufficiently versatile and flexible to be included in a wider range of set-ups with non-Naim sources and loudspeakers – which, in part, is how we tested it.

Mid-range

The £1,250 XS sits between the NAIT 5i and the SUPERNAIT in terms of pricing and position in the company's integrated-amplifier hierarchy.

Comparing it with these two amplifiers (£735 and £2,350 respectively) demonstrates how well it sits between them performance-wise too. While the NAIT 5i is a very respectable and musically informative performer, the XS clearly has the beating of it in an A-B comparison.

Not only does it sound cosmetically more polished and capable than the NAIT 5i, which sometimes sounds a little raw alongside the XS, but it also seems more temporally organised and better able to define the space between notes, as well as the note shape itself.

In this respect its performance moves closer to that of the range-topping SUPERNAIT, an amplifier whose communicative skills and expressive ability are comfortably in the premier league.

Enjoyable performance

The XS, as one might expect, exhibits the long-established Naim characteristics of crisp timing, precise pitch determination and rhythmic urgency, all of which imbue appropriate music with vitality and pace. However, like more recently released Naim components and, perhaps, unlike Naim amplifiers of yore, it also possesses what used to be called 'Round earth' (as opposed to flat earth) qualities.

This is perhaps most noticeable in the way that it handles the didgeridoo on Vivid curve's Live at Edgefield CD – although the instrument sits at the back of the mix on tracks such as Hundred Naked Kangaroos, the XS renders its contribution in almost microscopic detail, presenting it not as a monotonous, continuous drone, but as a progression of differently intoned phrases, each of which adds colour, expression and individuality to the music.

In truth, analysing the performance in terms of specifics is rather missing the point. The XS is designed to make music more communicative and enjoyable on an emotional level, and in that respect it fully achieves what it sets out to do. It enables listeners to appreciate those often subtle effects performers include that instantly raise a smile or a nod of recognition when you hear them.

This communicative ability, which elevates the baby Naim's performance way above that of many far more expensive highend amplifiers, is almost certainly a result of the design's speed and lack of background clutter. When music is present, you hear it; when it's not, you hear nothing. There's no smearing or blurring with the XS: notes begin and end with near clinical precision, regardless of their depth in the mix.

Impressive soundstage

This brings us neatly to another subject that isn't traditionally regarded as a Naim forte: soundstaging.

Partner the XS with suitable loudspeakers and you may well be surprised by the depth and width of the images it can cast, as well as the solidity and stability of the elements within that stage.

Given a sympathetic recording, those elements are presented within a distinct acoustic environment, which can be wet or dry depending on the amount of reverberation it offers. The air surrounding percussion instruments and percussive elements – for example, cymbal strikes or artificial harmonics on a guitar – truly enhances the credibility of the portrayal the amplifier provides.

The downside of this scrutiny is that sometimes the truth doesn't sound as good as the performance through a less revealing amplifier: the XS paints a warts-and-all picture of recordings, exposing overtly, for example, the fact that home-studio synthesized backing tracks can rarely match the genuine articles from a professional studio.

One favourite review recording closes with a track laid down by the artist in his home studio, compared to the rest of the CD, which is a live recording. The multi-track home brew sounds horribly artificial, gated and dry with lifeless timbre to the instruments. We doubt that was the effect the artist was aiming to achieve. If he'd had the opportunity to play back the track on the XS he might have realised his error.

Power with subtlety

The class of the Naim NAIT XS also shines through brilliantly on well-recorded classical music, where its acuity with instrumental timbre and ability to reveal playing nuances come straight to the fore.

On the London chamber orchestra recording of Dave heath's The Frontier, not only can you appreciate the fine acoustic of the venue and the rich tonality of the strings, but also the gusto with which the players approach the music and the striking effects of the unusual playing techniques employed.

Throughout this entire CD, the XS majors on blending power with subtlety, easily conveying the full weight and might of the orchestra playing fortissimo, while at the same time showing remarkable finesse and delicacy in revealing the composition's detailing and the dynamics of the instrumentalists' playing.

With the XS, Naim continues to broaden the appeal of the NAIT concept to encompass an ever wider range of listeners. Like the early NAITs it's a musically communicative, minimalist design, but now the performance is balanced by worthwhile sophistication and poise.