Roon Nucleus+ Network Music Server Review

September 19, 2020
Words and photos by Rafe Arnott

While streaming music services like Spotify, Qobuz or TIDAL reach millions of people every day, and have a focus on social listening and song or album sharing, the audiophile listening experience when it comes to network audio is pretty much the opposite of that.

Most audiophiles spend more time listening to the gear than the music and are usually trying hardest to hear what they hope is not there, in the case of digital audio: electronic noise.

This can be introduced to the signal from the multi-tasked laptops or PCs that many use to run digital-audio software applications. It can also come from corrupt AC lines, RF or EM hash piggy-backing the signal due to improper cable or component shielding, the spinning of attached network hard drives, perceived sub-par network routers and switches, etc. You can see how the fun of a shared Qobuz playlist might stop rather quickly for most of these people.

So, in an attempt to allay these hi-fi anxieties, digital music software platform Roon introduced the in-house designed Nucleus and Nucleus+ music servers. These are purpose-built solutions meant to completely replace PCs or laptops, and feature a dedicated Linux-based version of the Roon OS (ROCK – Roon Optimised Core Kit) and server software on their own HD for dealing exclusively with digital audio. With no moving parts, the Nucleus+ is equipped with an Intel i7 processor, 8GB of RAM*, PCM support up to 24-bit/384kHz and DSD128, two USB 3.0 USB ports, HDMI, Gigabit Ethernet, RF and EM shielding, a massive heat sink enclosure designed to also accept the installation of a second HD for music files, and an external power supply. *Nucleus comes with Intel i3 and 4GB of RAM

This is a plug ’n play solution that works seamlessly with Roon for accessing streaming music services. Whether you’re a digital audio noob or a super user, if you are a Roon subscriber and prefer this platform for handling local music files, online accounts, album and artist information then you will love the speed and power Nucleus brings to that experience.

If you’re not familiar with, or don’t understand what Roon is, I’ll use the company’s own description:
“Roon cleans up your music library, upgrades the metadata associated with your music, and provides a user interface that is far richer than anything else out there. Roon provides bit-perfect playback of lossy and lossless file formats, including high resolution audio content. Roon manages your audio renderers whether they be built-in sound devices, like your laptop’s audio output, a USB connected DAC, or even networked audio devices. Roon is an application suite that must be installed. It is not a website. It runs on Macs, Windows PCs and Tablets, Linux PCs, Android Tablets, Apple iPads and iPhones. Roon uses your music files, Internet Radio streams, and content from the TIDAL and Qobuz streaming music services, but doesn’t come with any music.”

How does Roon work exactly, what makes it better than the TIDAL, or Qobuz apps on their own (it doesn’t support Spotify, so that’s a non-starter for many) and why should you care about a small dark grey box that costs thousands of dollars when you can just use a laptop or PC?

Most people won’t care, and will never care. For the average music listener technology geared towards audiophiles is niche at best and utterly impenetrable at worst. But for those who take their music listening experience seriously, a box like the Nucleus+ is a good deal for what it offers – namely an audio appliance that works without issues, peace of mind from audio nervosa and a noticeable uptick in speed of browsing and playback performance over many other DIY or consumer solutions.

How Roon works can be broken up into three distinct sections: the first is the Roon Core, which is the brain of the operation, residing on the Nucleus HD (or your laptop or PC, NUC, etc.) and oversees the indexing, presentation and management of all your audio assets and streaming content. The second is the Roon App, which gets installed on your iPad, iPhone, Tablet, Smartphone, etc. and is the remote control for the Core and allows you to use the highly intuitive and in-depth Roon GUI without putting undo processing cycles on said devices. Your DACs, network players or combos thereof are the third pillar of this platform and receive the music streamed from the Core.

At roughly 5.5 pounds without a second internal SSD, and about 8 inches wide, the Nucleus can be tucked away.

When compared to my dedicated MacBook Air 11-inch that I use as my Roon Core (only runs Roon other than the OS) the most immediate difference was a lowered noise floor and the speed that I was able to browse files off my iPad 2 Mini and iPhone 7 Plus. This was not a subtle difference in either category, and made for a much smoother and enjoyable Roon-based listening experience right out of the gate. I currently have more than 2,000 albums in my Roon library, most are a mix of TIDAL 16-bit/44.1kHz or MQA files and Qobuz 16-bit/44.1kHz or higher-resolution albums. About 400 are CD rips or high-res downloads – not much compared to many digital-audio consumers. Then again, I’m picky and don’t usually add an album to my library until I’ve listened to at least part of it and decide I’d like to hear it again.

For those unfamiliar with Roon software, it’s most current version – Valence, 1.7, build 610 – is dead easy to use. Kids or the elderly are just as quick on it as 20, 30 or 40-somethings, which in itself speaks volumes about the company’s research and development of the app. When it comes to searches, I’ve rarely not found an LP, song or artist I’ve wanted to hear between pulling from TIDAL and Qobuz, and having Roon to navigate both streaming services simultaneously is without doubt convenient. But, the software’s main strength lies in the practically universal envelope of information it puts at your fingertips related to the music – and the way it handles visual presentation of said data. The deep dive of collated material one can spiral down on every artist, album or track is almost unsettling because of the sheer amount of tangential specifics available regarding related artists or groups, side projects, appearances with, writing credits, etc. that the Roon algorithm provides by harvesting information on the Internet. Another well enabled feature is the “Recommended For You” section of the interface which previews albums Roon thinks you’ll dig based on what you’ve been searching for and listening to. If you think Google is good, this is some next-level shit. It’s not a stretch to say that I’ve had exposure to more new music that I actually really like (and love) through this feature than anything or anyone else. Ever.

More of the sonic cues I look for in a great recording made it to DAC/Network Players like the
Naim NDX 2 through the Nucleus+ thanks to its low noise floor..

Using the Nucleus+ connected to an external 2TB USB 3.0 HD through a variety of DACs and DAC/Network Players I had available showed just how deft a sonic hand the company had dealt consumers. Specifically in relation to the average laptop or PC. Roon engineers obsessive attention to detail in the low-noise circuitry design, internal-component isolation, high-grade hardware, optimized software, RF/EM shielding employed, and external power supply have shown a demonstrable difference in how quickly one can navigate large swaths of not only album choices and searches, but associated metadata which Roon culls to accompany every music title. There was also no discernable lag in playback of any file type. Everything loads and plays back without delay – processing speed my Air could simply not match.

Whether it was a Naim NDX 2, a Linn Klimax DSM or a totaldac d1-direct DAC – all exceedingly revealing instruments of digital music reproduction – through the Nucleus+ there was a palpable addition of texture and tactility to drum skins being brushed and bows on the strings of wooden-bodied instruments. There was more shading to tonal and timbral colour in cymbal shimmer and decay, the blaat of a trumpet, the weight and scale of a piano hit harder, and the brassy honk of saxophone was honkier. It did this because the Nucleus+ did a better job of allowing more detail in the recording to come through than my Air could. Was it as good at allowing more information to be passed above the noise floor than an Aurender W20? No, it was not. But neither should it since the W20 costs roughly 12 times as much and doesn’t run Roon. So why mention it? Because I had a W20 at home and compared the two.

Placement agnostic in my experience, but not cable agnostic, the Nucleus+ displayed the ability to have its sonic signature affected by swapping out both USB and Network cables between it and the DAC it was feeding, much less so if from from a router or switch to the Nucleus. I swapped out several ethernet and USB cables over the course of many months with the Roon box, so keep that in mind if you’re noticing something you don’t like (or like) with the cable you’re using. You can always fine-tune the flavour if you want.

In the final analysis the most enjoyable trait of the Nucleus+ was the fact that you simply forgot all about it when in use. The Nucleus removed itself from the listening equation because it was doing nothing but what it was designed to do: pass along a digital-audio signal unmolested. There’s not much more anyone can ask from a hi-fi component but that. The fact that it did this not-so-simple act with only a handful of crashes, stalls, and hangs over more than a year of day-in and day-out service is a minor miracle considering the complexity of network streaming from third party music services over the Internet. If you don’t feel like building your own audiophile computer-in-a-box, are tired of using a PC for something it’s not designed to do, take your digital-audio playback seriously, just want to listen to the music not the gear, and use Roon exclusively, then grabbing a Nucleus or Nucleus+ is a no-brainer.

The basics of high-speed digital connections are represented well on the Nucleus…
a Coax out would’ve been nice though.