Naim Audio Uniti Atom Headphone Edition Review
David Price tries the new can-friendly version of Salisbury’s popular streaming DAC system for size…
Uniti Atom Headphone Edition
Living as I do in a house full of hi-fi, sometimes it’s hard to empathise with other, less fortunate beings than myself. In my listening room, I have four turntables, two power amps, as many preamps, a DAC/preamp and a headphone amplifier – plus a large pair of loudspeakers and numerous pairs of headphones. Then there are my records, CDs, tapes and a NAS drive, which stretch out down the hall – plus three more systems around the house for good measure.
When my friends come round, they are always impressed with the system in my listening room and think it shows how serious I am about sound. It’s an interesting talking point at dinner parties, but not the sort of arrangement that any of them would ever countenance in their own homes. Needless to say, this is why many of them now have a Sonos; they love its ease-of-use, if not so much perhaps its performance.
That’s why Naim’s new Uniti Atom Headphone Edition is such an interesting prospect. It’s one of the few products that I’ve come across that comes close to giving these sort of folk the best of both worlds – at a price that’s just about affordable to those serious about sound. It might have toy-like proportions, a flashy volume knob and a snazzy bright display, but it’s a really decent sounding bit of kit that performs multiple roles unexpectedly well. It’s both a great ‘lifestyle system’ to which you can easily add small powered speakers and a sub, and a gateway drug to a proper high end separates streaming system with headphone functionality.
As its name suggests, Naim Audio is marketing the Uniti Atom Headphone Edition as a serious headphone amp that’s also a DAC/preamp and streamer – but it’s actually able to fulfil all these roles very capably and in no particular order. In my system, it replaced – for the review period at least – a DAC, preamp, streamer and headphone amp, and has been feeding two expensive power amps (Sony TA-N86B Class A solid-state and World Audio K5881 tube), which in turn drive my Yamaha NS-1000M loudspeakers. It has done all of this so deftly that many people wishing to de-clutter, clean up or downsize their multi-box high-end systems could actually consider it as a solution.
The baby Naim has also proved unusually female-friendly. Several friends and family members of mine who’d never normally pay any attention to my hi-fi have remarked upon it. These ladies may have referred to it as “a gadget” – a sin in my book nearly as heinous as calling an LP record “a vinyl” – but at least they were interested enough to comment on it. Indeed, I think the Uniti Atom HE has elicited more attention than anything I’ve had in for review since Meridian’s original Sooloos, some fifteen or so years ago!
Naim Audio’s Clare Newsome told me it has been designed to appeal to the growing number of people who do most of their listening via headphones at home or work. “This makes it ideal to use where space is at a premium – it could make a superb bedroom system, for example, as well as sitting pretty alongside your favourite chair or on your desktop.” She adds: “It’s also an excellent streaming preamplifier, which could really suit a customer whom is looking for a compact preamp to use with either active speakers or a power amp.”
Naim’s first one-box system – the NaimUniti – came out in 2009, and the latest Uniti series upon which this is based has been on sale since mid-2017. Now in 2021, we have the Uniti Atom Headphone Edition. As per all its family relations, this compact (95x245x265mm, 7kg) box has a lovely fascia with a large, crisp backlit LCD screen, an intuitive user interface and a highly house-trained and friendly app. It can play out music via myriad sources, including one pair of analogue RCA phono inputs, three digital inputs (two TOSLINK up to 96kHz; one coaxial) and its built-in streamer.
The latter works so well thanks to Naim’s long-time involvement with the technology; it’s Roon Ready, of course, and does all the other usual stuff like TIDAL, Spotify and internet radio. I ended up playing Qobuz a lot, which is getting ever better with all the hi-res content it now has. There’s also AirPlay 2 support, UPnP, Chromecast built-in and USB, supporting playback from memory sticks or drives up to 32-bit/384kHz resolution. There is no support for MQA currently.
The Atom HE uses the same Naim streaming platform that runs from the Mu-so 2nd Generation wireless speaker family, through the Uniti range, right up to the company’s flagship ND 555 player. The platform is also designed to be updated as new technologies and services arise – for example, Tidal Connect support will be added later this summer, the company says. The Naim app brings together the company’s current streaming products with previous-generation designs like the original Mu-so and Uniti range, etc. All can be controlled from this same app and work together in multi-room set-ups.
Then we come to its headphone skills. There’s a choice of 4.4mm Pentaconn balanced output, 4-pin XLR balanced out, and ye olde 6.35mm (quarter inch) unbalanced jack socket. Driving these is a newly designed and totally bespoke 1.5W RMS per channel (into 16 ohms) pure Class A amplifier, said to be suitable for headphones from 16 ohms up. Output impedance is said to be 4.7 ohms on all outputs. Cleverly, with really hard loads, the headphone amp switches into Class AB to deliver the last dollop of its power.
Naim’s electronics whizz Steve Sells explained it thus: “When driving, say 600 ohms at full volume, the headphone amplifier will remain in Class A. Into 300 ohms at full volume, it stays in Class A for all except the last few dB. As the impedance of the headphones drops then the point at which it slides out of Class A gets lower. Dropping to 32 ohms, it will be pure Class A until approximately 3.2mW, and then seamlessly glide into Class AB for the remaining top 25dB. Remember that music is generally recorded around -20dB, so for all the musical nuances, it can be still considered Class A.”
Intriguingly, however, the Uniti Atom HE isn’t just the preamp section of the existing design with a headphone stage bolted on. There has been quite a lot of work done to the circuitry in general. “There are improvements at every point,” says Steve. “For example, the transformer has the same sized core as Uniti Atom and the same digital winding but has new analogue windings for the headphone amplifier. These have been appropriately scaled for the headphone amplifier – the voltage is lower so that it runs cooler allowing smaller, faster power transistors.”
I ran the Uniti Atom Headphone Edition as a streaming DAC/preamp, with regular headphone listening sessions too. It’s easy to set up, providing you follow the instructions; this done, you’ll soon be up and running with the Naim app talking to the unit seamlessly. You then end up working out your own way to use it – either via the app and/or the lovely top-mounted volume control knob or the surprisingly swanky Zigbee supplied remote control handset. Some cynics won’t like the rather stylised volume knob, but it actually makes the Naim far easier to work than many so-called ‘lifestyle’ systems I’ve tried over the years. This, combined with the front fascia mounted control buttons and excellent display, make for easy access to your desired music source.
The Naim app is excellent, but only up to a point. It provides an attractive and highly stable ‘tableau’ to access your various streaming services and is nice to use. However, geeks won’t be happy that it doesn’t display the sampling frequency or bit-depth on TIDAL while searching for tracks. With Qobuz, you can only see whether it’s “hi-res” or not, as opposed to how hi-res it is. That’s the joy of Roon of course, which the Naim also works with – one of its many benefits is that it sifts between the different versions of the albums available for you to stream.
When you’ve finally found the music you want and are streaming it, waving your hand in front of the display shows you what resolution you’re playing before it defaults back to the cover art. This is one of many thoughtful touches and shows the Naim has been designed rather than flung together. Much effort has obviously been expended to make playback as easy as possible via the app, including syncing the volume control on the unit and the app. It is streets ahead of what Naim was producing even just a few years ago.
Another fine feature is the headphone mode arrangement, which not only mutes the preamp outputs automatically when you plug your cans in but offers you a separate volume control for them. This means that if you’ve been listening to speakers loud and then switch to headphones, it remembers the last volume setting with headphones, so it doesn’t simply play the headphones at a similarly high level. The Naim is beautifully built and finished considering its price; there’s no sense that you’re buying something that’s meant for the cheap seats. People used to running high-end systems won’t feel they have come down in the world at all, living with this.
With its multitude of inputs and features, there’s a lot of ground to cover – so let’s start with the basics, shall we? Used as a DAC/preamplifier, the fundamental character of the Uniti Atom Headphone Edition is pretty neutral. Indeed it’s more so than I’d expected, considering where it sits in the market. Remember that to buy a streamer, DAC, preamp and headphone amp in separate boxes of the equivalent cost to this single box doesn’t leave much for each respective component. The Naim’s sound doesn’t stand out as being particularly forward, soft, hard or dull; in absolute terms, it’s a smidge on the crisp and dry side, but not much.
At the same time, it retains the company’s famed ‘pace, rhythm and timing’ – meaning that the music comes at you in a spirited and expressive way; it never sounds sat upon or leaden. This, combined with its basic neutrality, makes it fun to listen to all types of music from processed pop to fine classical recordings. For example, Second Sight by the Dolphin Brothers is a slick bit of late eighties pop, all Yamaha DX7s and Linn Drums. It was mixed to have a punchy but compressed sound, and the Naim rendered it with great precision when fed from my Cyrus CD Xt Signature disc transport. As well as an admirable clarity, the music bounced along with a highly propulsive bassline that made listening fun.
However, as proof of its intrinsic transparency, this little bit of kit can really raise its game when you feed it a better source. For example, a 24/96 PCM stream of Marillion’s Kayleigh via Qobuz was like flicking a switch. There was a good deal more texture to the recording, such as the grumbling bass notes from the opening synthesiser line and the lovely crisp hi-hat sound, which sparkled but didn’t grate. Vocals sounded more realistic and sat in space more comfortably. Switching recordings brought about a dramatic improvement in sound, and the Naim was obviously good enough to reflect the difference between them.
Soundstaging is impressive, too. Many one-box systems end up delivering a distinctly two-dimensional recorded acoustic that makes things sound like they’ve been squashed up against a glass plane directly in front of you. Not here, though, because the little Naim can also do a fair degree of depth perspective; we’re not talking a high end-style ‘walk around soundstage’ here, but it’s way better than you’d expect from something of this price.
Steely Dan’s King of the World streamed in hi-res from my Western Digital NAS clearly showed Donald Fagen’s vocals hanging back, just as they should. The better a system gets in my experience, the more he sounds like he’s singing from the other end of the hall – as there’s a lot of reverb and processing going on. This product conducted itself with great maturity, setting up a wide soundstage with numerous things going on within. This reminded me of what excellent recording and production values this amazing band had back in the day.
The more I asked of the Naim, the more it appeared able to give. There seems to be more detail, insight and finesse than I’ve heard from previous generations or variants of the Uniti. It can delve deep into a recording and scavenge out subtle spatial cues and harmonics that you’d think would be above its pay grade. One listen to Cafe Reggio’s from Isaac Hayes should persuade any doubters. The original early seventies Stax double LP sounds spectacular, one of the finest analogue recordings I’ve ever heard. I cued up a hi-res PCM transfer from my NAS drive, and the Uniti Atom HE didn’t disappoint. It wasn’t the finest result I’ve ever heard, but I’m more used to this sort of sound from standalone streamers that cost more than the Naim. Fed a high-quality digital datastream, this product can really pick up its proverbial skirts and run.
The analogue input is also rather good, albeit not quite as stellar as via my NAS drive. Naim Audio says this goes through the system’s internal digital signal processing, which can often be the death knell of affordable one-box systems trying to do analogue. I hooked up a Technics SL-1200G turntable (tracking a van den Hul Frog moving coil cartridge and via an ANT Audio Kora 3T SE phono stage) to the RCA phono input, and was pleasantly surprised. My well-worn pressing of Crosby, Stills, Nash’s Wooden Ships sounded sweet, with lots of atmosphere and space to the proceedings, just as it should be. The track’s distinctive, lilting rhythms were nicely communicated, too – although an all-analogue system does it better still. All the same, this will be all that mainstream listeners will ever need – it certainly doesn’t do vinyl a disservice.
Any headphone stage would be pretty pointless if the Naim wasn’t much cop as a streamer, UPnP player and DAC, let alone a preamp. This has to go without saying for its headphone amp to succeed, and happily, it does. I tried a wide range of cans, including Jays v-Jays, Oppo PM-1s, Philips Fidelio X3s, Beyer Amirons and Sennheiser HD600s – and found it hard to find fault with any of them. Indeed, my conclusion was that the headphone stage signposted the vast differences in sound quality between the various headphones I tried, rather than drawing attention to itself in any way.
By way of example, the Uniti Atom Headphone Edition served up a squeaky-clean and detailed yet dynamic rendition of Simple Minds’ soaring New Gold Dream, with energy and finesse in equal measure. This early eighties analogue recording is superb, yet only serious front ends will tell you – it can sound opaque and muddy through lesser equipment. I was seriously impressed by what I heard, as there’s very little apparent difference to the Naim’s preamp sound. That means a natural, spacious and engaging performance with a good deal of dynamics and a vibrant portrayal of fine detail, such as the texture on the synthesisers. This song’s bass line can sound plodding through poor headphone amps but was tuneful and propulsive here. Cymbals shimmered, and the snare drums hit home with bite.
Finally, in my quest to run the gamut of its features, I tried the Bluetooth input. It paired to my iPhone almost instantaneously and went on to give a great rendition of Felt’s Primitive Painters. This eighties indie classic can sound like one long dirge through lesser equipment, but the Naim made a valiant stab at it – making this fairly low-resolution AAC file seem quite acceptable. The music shuffled along really pleasingly, with a surprising smoothness to the chiming guitar sound and crashing cymbal work. It was perfectly good for background listening and underlined this product’s obvious strength in depth.
There is no shortage of rivals for the Uniti Atom Headphone Edition, which is why Naim Audio has kept its pricing keen – particularly for something that’s designed and manufactured in Salisbury, England, rather than a country on the other side of the world with lower overheads. Yet performance hasn’t been paired down with it, as this little box combines excellent real-world functionality with super sound at the price. This applies across all sources and whether it’s being used as a preamplifier or a headphone amp – which is no small feat.
This is not a giant-killing product that’s better than a high end streaming DAC preamp/headphone amplifier – in outright terms, the sound is a little lacking in depth and resolution. Yet you’ll have to pay a good deal more to find something that’s comprehensively better, and no systems that I can think of are easier to use. Also, I love the fact that it doesn’t have a power amp built-in, meaning that you’re free to pair it up with a set of active loudspeakers or add your own power amp as you see fit. A highly talented all-rounder with a style and charm of its own, it’s an essential audition if you’re after a compact, quality sound solution.
David started his career in 1993 writing for Hi-Fi World and went on to edit the magazine for nearly a decade. He was then made Editor of Hi-Fi Choice and continued to freelance for it and Hi-Fi News until becoming StereoNET’s Editor-in-Chief.
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