Roon / ND555 - optimising sound quality

Prefer convenience and user interface of Roon (for my Uniticore / Tidal / Qobuz-sourced material) over using Naim app and consequently have bought a lifetime Roon subscription. Currently Roon runs on a top-spec 2012 i7 Mac Mini (with factory SSD and no other apps running but no hardware modifications).

I tend to find, though, that playing via the Naim app (ie. not using Roon) gives the best sound quality.

So here is my question – in an attempt to raise the quality of Roon playback to the highest level, is there any mileage in replacing the Mac Mini with a Roon Nucleus (+)? Am not interested in putting together a Roon Nuc PC, instead my question is specifically with regards to the Roon Nucleus hardware and I’d be interested in other users’ experience. Am not using DSP or any signal modification within Roon.

Still work long hours (not semiretired) and don’t have any time / patience for trying out Ethernet cables, fancy switch tweaks etc before anyone mentions it. I do have the ND555 and UnitiCore on a Cisco 2960 switch (with the rest of the home network confined to a set of Netgear Prosafe switches) and that is pretty much as far I am willing to go with that side of things. (The Mac Mini was on the Cisco switch but I took it off when I found that doing so made Roon snappier in response and specifically removed the ‘looking for server’ message which Roon gives momentarily on starting the app - which I attributed to the fact that the Netgear switch which the Mac Mini is now on is a gigabit device whereas the Cisco isn’t).

All input appreciated.

Here very simply put are what I have found with my Naim ND555 in a 500 system:

  1. Fanless QNap NAS sounded slightly clearer, more dynamic and detailed/textured than Naim Core using Minim/Asset with all other functions closed down
  2. Under these circumstances Roon was about par
  3. Roon Nucleus+ improved on this for local and Qobuz
  4. Adding a Sean Jacobs / Custom HiFi Cables DC3 linear power supply improved this still further
  5. The new firmware update for the ND555 brings a sound quality improvement that diminishes the differences offered by cables/switches but these are still readily perceptible

Hope that helps. I’m very happy with the Nucleus. I believe it is underrated in terms of what it brings to the party. Depending on your dealer you should be able to get a home demo. Finally, after comparisons, for SQ, I recommend the Samsung Evo SSD that Roon also recommend as an internal SSD, which gives a very compact solution, backing up to separate HDD and to Backburner in the Cloud…

PS: I don’t use any of the DSP options

Hi - if using the inbuilt DAC in the ND555 then i would leave all the Roon settings for the ND555 as default - otherwise if using as a transport only - possibly unlikely with a ND555 - then set at 24 bit.

Ensure all the DSP and signal conditioning settings are disabled for max SQ.
The actual Roon server really makes no real difference to SQ other than slight variances due to the OS and physical network adapter on inter frame timing consistency - which on the newer Naim streamers is largely mitigated anyway. If you want to use the method described below - you will need a bit of CPU power - which for most small platforms other than tiny NAS processors or early RPis will be fine.

If you really want the added benefit of adjusting the eq of the sound for your room/speakers etc, then you can manually create FIR filter kernels using REW or equivalent which will be the most benign to phase distortions etc as it uses an FIR approach with a relatively large number of taps or kernel sample values. Roon refer to this method somewhat obscurely as ‘convolution’ - which actually simply means the DSP number series equivalent of ‘multiplication’ which is a mathematics technique FIR based DSP uses. Again when you make the filter kernels (for each sample rate), don’t just rely on automation with a mic, use that as a basis then manual trial and error on top of that to smooth out any large variations and optimise for taste.


I don’t think the slower 10/100 speed of the Cisco ports will be a problem in itself, as this is more than enough to cope with the demands of a music server and streamer. If discovery is slower, I wonder if the Cisco, on its default settings, is just taking a little longer. Still, if it’s working OK now, probably best to leave it alone if you don’t fancy learning how to console into the switch and change settings.
(As an aside, most 2960s have one or two separate ports on the R side which are GB when the other 8 are 10/100. This might be useful if, say, you want to transfer a large amount of data quickly.)

No, will be almost certainly nothing to do with port speed. More likely that there is an issue with the IGMP version, or multicast protocol running on your server where Roon core resides or elsewhere on your home network - either way as described it points to a fault or issue somewhere. More advanced devices like the Cisco2960 are designed to work correctly for reliable and more deterministic behaviour. Many consumer devices are less fussy - and can work with faults and issues on the network as they don’t support these higher performing protocols - as they don’t need to work in quality reliable setups.
You can log onto your 2960 and it can likely tell you if there is an issue - and even possibly who the guilty culprit is - the power and advantage of using a managed switch.

If you can log onto your switch and interrogate it I can advise you what to do to see where and if there is a faulty device on your network

FWI no delay on my system when it 1 or even 2 Ciscos

Thanks all. Will put Mac Mini back on Cisco and recheck Roon performance. Will report back.

Michaelb - With your Nucleus / LPS etc do you now find that Roon is equal in SQ to using ND555 with Naim app alone?

In meantime, am hopeful others who have moved to Roon Nucleus will chip in with the experience…

For Quobuz Roon sounds better than the Naim app. The albums on my hard disk can only be played using Roon from the Nucleus so I can’t compare there, but it’s definitely quite a bit better than the Core I demoed last year.

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Whilst I use an NUC rather than a Nucleus (which is an NUC in a fancy coat) and an NDS served through a bridge rather than an ND555 my experience may be relevant.

Before purchasing I did do a lot of listening to compare with my previous arrangement which was a QNAP NAS running Asset.

I cannot detect any difference between the two for local files and Tidal sounds the same to me as local files when played via Roon. Tidal through the Naim application is inferior to local files. I’ve not tried Qobuz.

I know you say you are not interesting in putting together an NUC but it really was very straightforward. I had it up and running in an hour, the database restore too longer than the small job of installing the memory and storage and loading up ROCK.

Either a Nucleus or an NUC are excellent solutions, they just run and update themselves, there is no admin required at all once running.


The Nucleus range is over priced for what it is and not that good at heat dissipation when it is working hard if any DSP is used. There are a number of other options like the InsideTech Fanless Roon Rock Music Server - Intel i3, i5, i7 or have a look at Audiostore and SmallGreen Computer in the US. i7 is the way to go if you have large library it make the performance very snappy, (i9s are appearing but only needed to run the likes of HDplayer with a lot of DSP). A suitable linear PS is a sensible buy and use it solo to send your music from a fan-less nas or a Melco/Innuo/Antipodes to your ND555.

This is my InsideTech on a HDPLEX 100w, Melco to Naim NDX2


The Nucleus is quite carefully designed with one purpose in mind. Even the processor choices made took keeping noise levels to a minimum into consideration - it’s not all about processing power.

I have a Small Green Computer sonicTransporter i5, which sells for US $895 without internal storage, which I use as a my Roon core feeding ND5 XS2 via ethernet. Setup is effortless and sound quality is excellent both for local files (I have a 2 tb internal SSD in my sonicTransporter) and Qobuz. I also looked at the Nucleus and saw nothing that warranted paying greater price of Nucleus. SGC’s website e ship internationally.


A lot of people come down on the Nucleus because of the price, but don’t get home demos. Sadly I don’t know of any comparative evaluations that one can read online.

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Yes processing power is not necessarily a good thing it can add extra noise but will give better performance if you use HD player and DSP. Mine is exactly the same as a Neucleus + inside but has a better heat sink and board mounting. I had an overlap of the 2 for a week, my dealer has a loan Neucleus +, I’m sure if you listened long and hard enough you may convince yourself that you could hear a difference as with any 2 components but which you might prefer is any ones guess. But I chose the IsideTech and spent the difference on music with out any difficulty.


Thanks. It’s good to hear from someone who has actually done an audition rather than just looking at price and spec sheets. I’m not sure what you mean about the heat sinking, though. Roon put a lot of care into it and the case is effectively the heat sink. Mine barely gets warm.

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True it’s been designed to keep the unit efficienctly cool and the Nucleus version of RoonOS is slightly different to ROCK as it’s designed for fanless running and fanless thermal control as it’s factored in to thier design as it’s a custom case not an off the shelf one with unknown thermal data. ROCK assumes you have a fan for thermal control so not optimised for fanless systems. Roon warn of this and it could lead to lower life expectancy due to excessive heat that said I too run ROCK on a custom built fanless system and mines not even a NUC. I’m too tight to spend that much money on music server.

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Indead the cooler things are the better especially with a head less unit, you never know what is going on until it happens. Hence my aluminium heat sink to the outside of the case.

I spent about $650 building a NUC8i7 with more memory and OS SSD storage (16GBs RAM, 250GB M.2 SSD) than it needs, and 1 TB SSD for music file storage. I haven’t bothered with fanless case or LPS, and it sounds great. Naim’s native Qobuz support sounds no better than running it through Roon on the NUC.

Using the guides on the Roon website I had the NUC assembled and up and running with ROCK within an hour. Restoring my Roon database didn’t take long, and I copied my 450GBs of ripped CDs and highres FLAC files overnight. That was half a year ago. Since then I have spent no time dealing with it. It’s now just an appliance that works.

Nothing played directly from the Naim app sounds any better than playing from Roon on my NUC with fans and stock power supply.


I run my Roon Core on an iMac running in the back ground, and send RAAT to my NDX2 via ethernet.

Underneath the covers there is a slight advantage to UPnP over RAAT with the new Naim architecture - which leads to a subtle sound performance advantage - although I use an off board DAC on my NDX2 so the differences are even smaller.

The differences are to do with the media transfer strategy - UPnP will transfer really quickly if the source media is available with the new NAim streamers - meaning the network stack works more efficiently.

With RAAT with what I have seen the transfer is more in keeping with the legacy streaming UPnP architecture and so is more drip feed - and so the network stack is working harder in the streamer… all very subtle in terms of SQ - but some of us do notice these things


Interesting - Qobuz still sounds better through Roon on my system. I was thinking this was maybe because the ND555 had less work to do that way…