Hi folks, and welcome to this month’s article from us here at Audio T Brighton. We’re in for a bit of a headphone journey this month because the streaming DAC/pre-amp in question is something I use personally on a daily basis. Let’s dive in and let you know my thoughts on this little marvel. Welcome to a review of the Naim Uniti Atom HE.

Naim Uniti Atom Headphone Edition...

Released as an addition to the Naim Uniti Atom during the lock-down in 2020, the Naim Uniti Atom HE is a useful alternative package for the personal listener, without foregoing flexibility to the budding audiophile when playing back through some speakers, with the addition of a power amp or active speakers, of course. More on that feature later.

HE is very well connected...

At a glance, the Naim Uniti Atom HE looks virtually identical to the standard Naim Uniti Atom, so let’s summarise the similarities/differences because the retail price of both units are the same.

Naim Uniti Atom v Naim Uniti Atom HE

Ethernet/Wireless - Ethernet/Wireless
no phono stage - no phono stage
3.5mm headphone input - 6.35mm input, 4.4mm & XLR balanced
HDMI eARC input - N/A
40W/ch into 8ohms amp - Discrete headphone amp (1.5W/16ohm)
Both feature 2 x Toslink, 1 x Coax inputs, 1 x analogue RCA input, 2 x USB storage

If your primary listening is through a pair of loudspeakers, then the Naim Uniti Atom is a unit that performs superbly at the price, really looks the part, offers a good headphone output, connects to your T.V. and only needs a turntable and phono stage to be added separately to finish off a quality stereo system you’ll be happy with for many years. However if your raison d’etre is towards personal listening via a pair of headphones, then the Naim Uniti Atom HE really comes into its own.

Armed with 3 headphone outputs; a standard single-ended 1/4 inch jack on the front of the unit allows playback through the majority of cans, or if you’re more serious about your headphone playback, then two balanced connections are available; a 4.4mm Pentaconn on the front panel and a 4-pin XLR on the rear of the unit. The two outputs on the front automatically mute the pre-amp outputs on the rear, useful if you have a power amplifier connected to speakers. The rear balanced XLR output doesn’t mute the speakers, so you’ll have to use the headphone/preamp selector switch on the top-left of the front panel to make your choice. However, you can also make your output selection with headphones connected to one of the two jack sockets on the front panel if you wish, the switch usefully lighting up with a headphone symbol when connected to the headphone output.

Balanced or single-ended headphone output?

Balanced inputs/outputs are a hot topic in the hi-fi world at the moment, so let’s briefly discuss their pros and cons. Before we start though, we need to sing the praises of the DIN connections that Naim have used on their systems for a number of decades. The noise and grounding benefits of DIN are such that Naim still recommends their use on sonic grounds, where possible, but they are not widely used around the world which limits connectivity across brands when mixing and matching hi-fi components. Naim have opened the doors of compatibility across the world by incorporating balanced connections on their new products in the Naim 200 and Naim 300 series released in 2022/23.

naim uniti atom he with focal clear MG headphones

So why use the balanced connections on the Naim Uniti Atom HE?

The main reason is one shared with the professional audio industry. Noise is an unfortunate by-product of electronics, wi-fi and long cable runs - just ask any guitarist! Unfortunately, as well as sending a signal along a copper cable, the cable often acts as an antenna for RFI and EMI noise. Proper shielding and balanced connections can help reduce noise, especially over a longer cable length. For shorter lengths, like those often encountered in domestic use, single ended RCA connections may be better, as advocated by companies like Linn, but your mileage may vary depending on how noisy your electrical environment is.

Personally, I run a longer length cable (5 metres) so I can sit or lie down on my sofa when late-night listening. I also like the uncluttered look on the front fascia and robustness of the 4-pin balanced XLR connector in the long term, so I chose a balanced cable termination, but that is just me!

HE, HE, HE, this thing is no joke...

The Naim Uniti Atom HE is a diminutive device, only occupying a half-width profile, meaning placement is somewhat easier than for a full-scale system. A small table or shelf near a mains outlet, along with a good pair of headphones and a cable of a decent length is all you need!

The original Naim Uniti Atom had a respectable headphone performance but the Naim Uniti Atom HE’s headphone outputs really do play in a different league! Detail, separation and staging of instruments in the mix are far clearer, with dynamic contrasts superior in both macro and micro-dynamic domains, especially with a pair of headphones that can do the Naim Uniti Atom HE’s discrete headphone stage justice.

Focal headphones are a suitable match, such as; Clear MG, Celestee, Stellia and Utopia. This is only to be expected as Focal and Naim are now sister companies and developed many of their product ranges in tandem. Other headphones that will work well are the Meze 109 Pro, Meze Empyrean 2’s.

Whatever headphones you decide to pair with the Naim Uniti Atom HE, you are sure to be mesmerised by the sound it produces, whether they be open or closed-back headphones. Naim’s engineers have clearly spent time fettling the amplifier section and it will drive both low and high impedance cans comfortably, quoting 1.5 Watts into a 16 Ohm load, so there will be few headphones that won’t be able to be driven by the Atom HE.

Naim Uniti Atom HE as a streaming DAC preamplifier...

In all the hullabaloo about the Naim Uniti Atom HE as an excellent headphone amplifier for personal listening, we may forget a major use case for our budding audiophiles. It also happens to be an excellent streamer/DAC/preamplifier!

The Atom HE has both single-ended RCA outputs and balanced, stereo XLR outputs in the preamp section. The ability to add a power amplifier of your own choice is a major bonus to this device, allowing the user to tailor their power amplifier choice to loudspeaker and room requirements.

We’ve found the Naim Uniti Atom HE pairs particularly well to the latest iteration of the Naim NAP 250 power amplifier.

Another benefit of separating the preamp from the poweramp is the ability to upgrade the components individually when you’re ready to do so, along with the inherent sonic benefits of doing so. A Naim NSC 222 streaming pre-amp would be a good partner for the Naim NAP 250, opening the door to better units further up the range, including the Naim NSS 333 streamer and Naim NAC 332 pre-amplifier.

From there, the sky really is the limit!