Naim Audio’s formidable reputation may have been built on the excellence of its amplification, but in recent years, it’s the quality of the company’s streaming products that have impressed the most.
The likes of the Uniti range have been hugely successful, opening the firm to a far wider customer base, while its traditional hi-fi streamers have long been benchmarks for others to be judged by.
Over the past few years, the company has invested heavily in a new generation streaming platform. This was first seen in the new Uniti system products with the Atom, Star and Nova gaining five-star reviews from us. Now we get a chance to try out that same platform when implemented in the company’s more premium hi-fi separates offerings, where a greater budget and more purity of purpose allows the engineers to optimise the performance with far less compromise.
The NDX 2 sits in the middle of the company’s three-strong hi-fi streamer line-up, and is about as well equipped as they come. There are no obvious holes in file compatibility and it can play up to 32-bit/384kHz PCM and DSD128.
Naim has been careful to be inclusive. There’s aptX HD Bluetooth alongside Apple Airplay, Spotify Connect and Chromecast. Tidal is also embedded and, as is increasingly common, it’s Roon-ready. In short, this is a product that is more than happy to play any music file you have, in any way you want.
Build quality is as good as we’ve come to expect from Naim. Its products don’t feel particularly luxurious, but they are invariably solidly made and nicely finished.
They tend to last decades too, thanks to a considered, no-nonsense approach to engineering, robust build and a service department that can still handle pretty much any product the company has ever made. Considering Naim was founded in the early 70s, that saying something.
The most obvious change over the first generation NDX is the use of a 5in full colour display that shows album art and track information. It’s a crisp screen and large enough to view from the other side of our test room.
Connectivity is what we would expect of a streamer of this kind. You can join your home network through ethernet or wirelessly. On paper, the wired option gives the best stability but we had no issues when using the wire-free option either.
There are pairs of coaxial and optical digital inputs, alongside two type A USBs (one on the front and back). The coaxials – a BNC and an RCA – can accept a 24-bit/192kHz signal, while the opticals are limited to 24-bit/96kHz feeds.
There’s also a coax digital output should you have an external digital-to-analogue converter to hand. Make sure it’s a good one though, as the number crunching circuit in the NDX 2 – based around a Burr-Brown PCM 1792 and mated to in-house filtering and supporting circuitry – is seriously capable.
Great care has been taken over how the digital signals are routed through the streamer, with the engineers using low-voltage differential signalling (LVDS) to reduce noise levels and induced jitter.
When it comes to analogue outputs the choice is between RCA and Naim’s preferred Din option. We side with Naim on this one, as the Din output tends to sound more expressive to our ears. Those looking for balanced XLR outputs will be disappointed. Naim doesn’t tend to fit these.
Naim NDX 2 tech specs
Storage 2x USB Type A
Screen 5in colour LCD display
Dimensions (hwd) 9 x 43 x 31cm
A power supply may not be the most glamorous part of an electronic circuit, but using a capable one is fundamental to getting a good performance. Few companies have prioritised this as much as Naim, and it has taken obsessive care over the power arrangements in the NDX 2.
This streamer has a low noise custom-designed toroidal transformer with separate windings for the digital and analogue sections. This kind of arrangement minimises any unwanted interactions between the sections, so helping sound performance.
If that isn’t enough, the company also makes add-on outboard power supplies to upgrade the NDX 2’s performance. You can connect an XPS DR (£3,999) or a 555PS DR (£6,999), should funds allow. It might seem strange to have the option of spending so much on outboard boxes when there’s already one fitted to a £4,999 product, but in our experience Naim’s add-on units genuinely take performance to another level, usually enough to justify the sizeable outlay.
A source of this streamer’s level positively demands a top class system. While we have no doubt that many NDX 2s will find a home partnered with sibling products, there’s nothing about its sonic character or engineering that suggests it won’t shine in other quality systems too.
We use the Naim in standard configuration, working under its own steam and plugged into our reference system of Gamut D3i/D200i amplifier and ATC SCM50 speakers. Interconnects and speakers cables are premium offerings from Chord Cables.
We begin with internet radio in the form of a BBC Radio 4 feed, using the highest quality option available (339kbps). We listen to Desert Island Discs followed by some political debate and the streamer’s presentation is crisp with voices coming through with expression and nuance. Though the sound couldn’t be confused for a hi-res stream, it’s still good enough to keep us listening longer than we should for strictly testing purposes.
We switch to Tidal and are impressed by the way the NDX 2 moves between feeds. It feels more responsive than the company’s previous generation of streaming products and any changes of source are made without issue or delay. This isn’t as common as it should be among premium-priced streaming products from relatively small manufacturers.
We try a range of music from Olafur Arnalds’ Late Night Tales from to the eclectic Cocoa Sugar set by the Young Fathers, and the Naim takes it all in stride. There’s a pleasing level of detail on offer and the dynamic finesse to work well with Arnalds’ mostly low-key tracks, while capturing the complex rhythmic framework superbly. There’s a confidence about the Naim’s presentation and a sense of organisation that is rare in streamers, even at this elevated level.
The Young Fathers set shows the Naim is capable of punch and power combined with an infectious sense of fun. While this streamer ticks all the boxes when it comes to hi-fi specifics, such as transparency, detail resolution and stereo focus, it never forgets to wrap it all in a blanket of entertainment.
That sentiment is emphasised once we start playing CD-quality and hi-res music files from our NAS unit. We get the expected increase in subtlety and expression combined with more fluid dynamics and more emphatic rhythmic drive.
It has no problem delivering large-scale symphonies such as Beethoven’s Fifth with the authority and dynamic punch they deserve. At the same time we’re aware of a stable and nicely layered stereo image and a nicely-judged tonal balance that is rounded enough to make even poorer recordings listenable.
There’s also enough insight to give the listener a clear view of instrumental textures and the composure to track multiple instrumental strands without losing sight of the whole.
The story is similarly positive with Bruce Springsteen’s High Hopes, where the Naim’s drive and forthright presentation renders the music with all the energy and attack it deserves. Yet there’s finesse where required, with Springsteen coming through with both determination and passion.
We work through our collection taking in Stravinsky, Coltrane, Prince and Drake and the NDX 2 never puts a foot wrong. It’s a willing companion, rendering each type of music with enthusiasm. While the sound takes the expected dip when using wireless technologies, such as Bluetooth and Airplay, we never feel short-changed. It all works seamlessly, as does the dedicated control app.
We add a 555PS DR outboard power supply, and though it’s a mighty expensive upgrade (£6,999), it improves the NDX 2’s sound significantly in all respects. As expected, the pairing sounds so much more muscular than the stand-alone player. It has the sonic authority to deliver the orchestral climaxes of Stravinsky’s The Rite Of Spring with an even greater dose of venom. Basslines are weightier and more powerful, while losing nothing in the way of grip and agility, and voices are just more expressive and human. Considering the price premium we expect no less.
For most, a stand-alone Naim NDX 2 will be all the streamer they could ever want. It is well made, carefully conceived and sounds excellent for the money. Naim also has a great track record on supporting its products, which really matters when the investment is as heavy as this. In short, buy the NDX 2 with confidence.
- Sound 5
- Features 5
- Build 5
Read all our Naim reviews