Article Index
Naim NAC N172 XS
p2 NAP 155XS power amp
p3 Jon Myles says
p4 Conclusion
p5 Measured Performance
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Naim's new NAC-N 172 XS preamplifier is a great sensory experience. Rafael Todes covers Classical and Jon Myles Rock, to really see what the Naim can do.


Looking down the specification of Naim's new NAC-N 172 XS preamp, it is surprising quite how much they have packed into this product – considering its price. I listened to it first through my own system with which I'm familiar, then through the Naim NAP 155 XS power amplifier they supplied. What follows is the sound through my system comprising VAC Auricle Musicblocs (valve) connected to B&W 802D loudspeakers.
    Listening to my stock hi-res digital audio collection, starting with the Rimsky-Korsakov “Dance of the Tumblers” on Chesky, through a USB memory stick inserted at the front of the player, I was immediately struck by the fact that the sound is significantly better than that I get from a Windows laptop, running Windows 7, Foobar with JPlay, and using the Halide Bridge as a SPDIF/USB convertor. The NAC-N 172 XS makes my current setup sound smudged and lacking in resolution. The Naim has a tautness in the bass, a speed of timing which makes the track rock impressively. The soundstage isn’t the most cavernous I’ve heard, the Weiss DAC202 does that better, but at £5000 it should!
    Having just found out about Hyperion Record’s growing collection of superbly recorded high-res material, I listened to the much under-appreciated Schumann D minor Violin Concerto, beautifully expounded by soloist Anthony Marwood. The preamp/DAC provides a warm, tonally rich account of the sound, without any nasty digital artefacts that sometimes can be present. Its superior sense of rhythm seems to enjoy the pulsating triplet quavers that pervade the first movement.
    Listening to a live concert recording I made of my quartet – the Allegri Quartet in Beethoven’s Op18 no6 Quartet 3rd movement, the Naim really captures the heat of the live concert. Tonally the balance isn’t bright, it is mellow at the top and unmistakably ‘Naim’ in the middle, but it reminds me of the digital I heard from the best USB/SPDIF convertors – a taught, rock-solid sound you get with very low jitter. The first-violin’s Amati violin sounds tonally transformed, as does my Brescian Maggini violin, not unattractively so, but it is not strictly timbrally accurate. The top end of the instrument is a little closed-in, giving it a slightly ‘pinched’ sound.
    I really appreciated the convenience of operating this preamp/player from my iPhone App; I could stream from any computer in the house easily, and the preamp also includes an Internet radio facility. Having just bought a Magnum Dynalab tuner, it makes Radio 3’s digital efforts via the Naim sound like plastic as there is very little tonal subtlety coming through, nevertheless it’s a useful armchair facility.
    Trying out some CD, in the form of Ray Gelato recorded by Linn Records, playing on my Bel Canto CD2, connected using a Chord S/PDIF Indigo Plus S/PDIF electrical cable, shows the NAC-N 172 XS acting as a DAC at its best. The percussion section seemed to have died and gone to hi-fi heaven: the high hat was as crisp as I’ve ever heard it, the drum kit positively sizzled, and the track had a driving energy which brought it alive (resurrection no less!).
    Turning to some classical fodder, Nielsen’s 4th Symphony the ‘Inextinguishable’ conducted by Herbert Blomstedt on Decca, a truly miserable epic work that finds redemption at the end, I hear a very different sonic picture emerging. The lack of stage depth of this naturally recorded symphony sounds a great deal less organic than through the Weiss DAC202. There is good textural separation of instruments for the most part, except the midrange which is a little more confused than I am used to, but there is a lack of layering on the stage depth front. The spatial integrity here is wanting. When the first violin section have a solo line, accompanied by the kettle drum, the resultant effect is extremely powerful, due to the preamp’s ability to separate the textures. When the rest of the orchestra rejoins the musical argument, the stage seems to shrink, and that wonderful clarity is lost.


It is rare that I find huge discrepancies in how a piece of hi-fi performs across different inputs, as with the NAC-N 172 XS preamplifier connected to the NAP 155 XS power amplifier Naim supplied to match it. There is normally a consistency to a unit’s characteristics that transcends what is playing. However, with this combination I was stumped.
    Using my all-valve Icon Audio PS3 phono stage feeding the preamp's analogue inputs yielded some stunningly powerful results from LP.  The first piece I listened to on my Inspire Monarch turntable with an Ortofon Cadenza Bronze in an SME V arm was a vintage recording of Stravinsky’s ‘The Rite of Spring’, Solti conducting the Chicago Symphony Orchestra on Decca. I noticed a much tighter rhythmic drive than my VAC Auricle Musicblocs (valve) are capable of, the extraordinary and indeed revolutionary use of polyrhythms being showcased with powerful yet precise drive. In particular the percussion was revelatory, and the power amp had ample resources to drive my B&W 802Ds to new exalted heights. Clearly the use of a valve phono stage with this combination is an interesting and fruitful one.
    Turning to CD and a grand orchestral work – Nielsen’s 4th Symphony, Blomstedt on Decca, played through my reference Bel Canto CD2 transport and both my Weiss DAC202 and the NAIM preamp's internal DAC, via electrical S/PDIF, yielded something of a disappointment. The soundstage had been collapsed compared to my valve monoblocs, and tonally, the midrange had lost the lovely tonal palette that I normally hear, swapping it for a pleasant but far less subtle version, a touch desiccated and rubberised.

   Yes, the bass was full and tight and highly attractive, but the midrange was missing a trick or two. The Weiss’ party piece of separating a violin section, enabling the listener to feel the weight of the different players’ contributions had disappeared, in its place was a narrow and smudged version which was far less involving. With this pre/power combination, I found it much harder to distinguish between the Weiss DAC and the internal DAC of the NAC-N 172 XS, the power amp in its transformations had minimised these differences.
    Similarly, listening to the tuner input, and in particular my Magnum Dynalab MD90TSE, a virtuoso amongst tuners, the subtleties that this great product can bring to a live Radio 3 broadcast were minimised. The tuner has an almost magical ability to introduce very accurate spatiality and weight to a live concert, with a gloriously beautiful oak-like timbre to the string sound. Under the Naim’s tutelage, this was eroded.
    Listening to Ray Gelato (CD) on Linn Records once more yielded an attractive and impressive result. Recorded using multi-tracking, rather than real 3D mic’ing, with heavy percussion, the sound was throbbing, vibrant, toe-tapping and fast.
    Obviously, I am skewed in my preferences towards the thermionic, but for me, the NAP 155 XS performed best with the combination of a valve phono stage, which seems a great antidote to the inherent characteristics of the power amp, the phono stage having a complex tonality in the midrange, superior spatiality, but a weak bottom end which lacks the tightness of Naim’s typical fare. The high-res nature of the Inspire Monarch contributed positively to the symbiosis of these components.
    The 155 XS has a creaminess to it that is different in quality to the brighter Naim kit of yesteryear, there has been a subtle but significant development to the ‘House Sound’ which I appreciate. I can also see that for music which is percussion-led, like the ‘Rite of Spring’ or Rock and Jazz, this power amp has the right qualities to be greatly attractive to a listener and will make many friends.
    For my own personal tastes and requirements, it doesn’t do enough in the areas I value and enjoy, quite in the right way. I also find that with my reviewer’s hat on, it is much harder to discern the contribution of other components in the chain as the NAP 155 XS lacks the transparency I need to hear subtle differences.

To say Naim has enthusiastically endorsed the brave new audiophile world of streaming music would be something of an understatement.
    Their range now stretches from the sub-£1000 UnitiQute to the heady heights of the flagship NDS which comes in at £6250 without power supply. And now comes the NAC-N 172 XS – basically a pre-amp with streaming facilities priced at £1650.
    In effect Naim sees it as an ideal starting point for adding network attached storage to an existing system – or alternatively starting afresh with one of the company’s own power amps. And let’s be frank, the latter combination is how the majority of 172s will be used because that’s what Naim owners do. Which in a way is shame – because this pre-amp is good enough to fit into a variety of systems.
    I’ll admit to being a bit of a Naim fan and regularly use a Supernait for everyday listening. And for those who say they don’t ‘get’ the Naim sound it’s worth noting that the overall balance of today’s equipment is a lot smoother than that of previous years. The NAC-N 172 XS is a case in point. Hooked up to the supplied NAP 155 XS and it showed its talents immediately. Yes, there’s still those almost clichéd Naim talents of pace and the ability to pull a rhythm out of almost any piece of music – but it does it without any sense of heavy-handedness.
    Barb Jungr’s ‘The Men I Love’ sounded deliciously rich – the Naim combination delivering a wide soundstage that positively oozed atmosphere. It has a seemingly natural affinity for vocals – Sinead O’Connor’s ‘Sean Nos-Nua’ sounding similarly detailed and vibrant.
    Switching to streaming from a RipNAS and the NAC’s ease of use was exemplary. It picked up the network immediately and the iPhone/iPad N-Stream App is simplicity itself to use. But it’s the music that counts and the Brian Eno/David Byrne ‘My Life In The Bush Of Ghosts’ collaboration played to the 172’s strengths. It’s an album of studio trickery and densely-layered samples which on the wrong system can sound a bewildering mess. But the Naim effortlessly portrayed the various strands, making it easy to hear right into the mix. It was the same with Steve Reich’s ‘Different Trains’ – the sometimes murky sampled vocals actually becoming crystal clear. Was streaming better than CD as some people claim? Probably not – but it’s certainly close.
    What was better though was a high-res download of the Neil Cowley Trio’s ‘The Face Of Mount Molehill’ played through the front-facing USB port. Here the strength of the Naim’s internal DAC showed itself – with a palpable sense of greater air and space around the instruments. Of the pairing, there’s no doubt the pre-amp is the star of the show.
    I briefly connected it to a Naim NAP 200 and the obvious benefits of this power-amp’s greater resolving power showed through. There was a definable leap in resolution and authority – showing the NAC-N 172 XS can hold its own in more expensive company.
    If there’s one minor criticism to be levelled at the unit it’s the
fact that if you’re a non-iPod / IPhone / iPad user then you’ll be stuck with the Naim remote control because at present there is no Android App. It’s not a deal-breaker, but it does negate some of the convenience of streaming.
    Apart from that, this is a very accomplished product from Naim. For the price it’s an excellent pre-amp offering all the connectivity you’ll probably ever need. Whether you are new to Naim or already a user, it’s well worth a listen.


It seems that this preamp offers a hell of a bang for the buck. It will suit recordings which employ smaller forces, and that are bass-driven from the bottom upwards, like rock and percussive jazz more than classical, or naturally recorded music. I particularly liked the way the USB memory stick at the front demonstrates a huge capability to play high-res material convincingly, much more so than any laptop solution I’ve had the pleasure to review. The iPhone iPad integration is superb, and even the built-in headphone amplifier performs well. Naim's NAC-N 172 XS preamplifier is a lot of well-engineered audio for the price.



A top quality preamp/network player from Naim that impressed both our reviewers. Great quality and value.

NAIM NAC-N 172 XS    £1650
Naim Audio
 +44 (0)1722 426600

The preamplifier has a useful x5 gain (14dB), that translates back to an input sensitivity of 200mV for 1V output to a power amplifier – enough to drive most power amps to full output. Frequency response measured 4Hz- 59kHz – adequately wide, especially by Naim standards as they commonly bandwidth limit their power amps to 22kHz. It overloads at 9V output, a normal enough figure.
    Frequency response through the electrical S/PDIF inputs reached just 24kHz (-1dB) with a 192kHz sample rate S/PDIF input, our analysis shows. A figure of around 35kHz is common and the hard upper limit is 96kHz, so this figure is low, but it is within Naim’s philosophy of bandwidth limiting.
    The optical S/PDIF worked reliably up to 96kHz sample rate and frequency response was identical to that for 192kHz sample rate, the upper -1dB limit being 24kHz and the -3dB limit 30kHz.
    This result also applied to USB when playing 24/96 wav files from a memory key, and when reading the same files from a computer via ethernet. Both USB and Ethernet were a little noisier than S/PDIF but the Naim was, all the same, quieter than most rivals, with a -98dB noise floor, IEC A weighted.
    Distortion at -60dB via S/PDIF measured 0.21% with a 16bit signal and 0.06% with a 24bit signal, both low values for the resolution available, although 24bit can manage 0.02% and noise raised the Naim value a trifle. All inputs gave this result. EIAJ Dynamic Range values were 102dB (good) for 16bit and 108dB for 24bit (fair).
    Naim use good quality, low noise receiver chips in their network products, including the NAC-N 172 XS digital preamp tested here. It yields excellent results. But Naim have chosen to bandwidth limit this preamp’s digital inputs to 24kHz (-1dB) even at 192kHz sample rate where 96kHz of analogue bandwidth is theoretically available.  This is in line with their power amps though, which are also bandwidth limited to 24kHz . It maintains the Naim warm, smooth top end. NK

Frequency response (-1dB)                4Hz-59kHz
Gain    x5 (14dB)
Overload    9V out

S/PDIF / USB / Ethernet
Frequency response (-1dB)
192k sample rate    4Hz - 24kHz
Distortion (16/24bit)    %    0dB    0.04 / 0.04
-60dB    0.21 / 0.06
Separation (1kHz)     112dB
Noise USB (IEC A)    -98dB
Dynamic range    102 / 108dB
Output    9V max






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