Relative quality of streaming 'transport' - isn't digital just digital?

Hello - new here!

Would very much welcome the collective advice of the forum please!

I’m considering upgrading my streamer and DAC and can’t get my head around the perennial question about the quality of the digital output of one streamer vs another.

Leaving aside the functions / high-res / file types and looks of the unit, how can the SPDIF output from a £400 player (such as a Sonos for instance) be ‘better’ (however you define it) than a £4,000 streaming “transport” like an Auralic Aries G2. Assuming they are connected to the same DAC, amp and speakers.

Jitter was the only thing that people were talking about but since more decent DACs reclock the input, doesn’t that effectively remove the issue?

I’d be very interested in peoples’ view on this.

No, it does not. It depends on the receiving DAC, for example the Chord Dave does it better than the Chord Hugo.

Again, the quality of the digital transport output is not the same between different devices. Can a Yamaha CD player be better than a Naim CDS3, if they are both used as digital transporters?

@Simon-in-Suffolk can tell you more.

Can I ask what you mean by Digital is just digital… because it is, just like analogue is just like analogue… but it tells you nothing about the signal being carried.
Remember in encoded signals, there are out of band signals such as unwanted interference or side effects along with the wanted signal.
Also with a clocked signal such as Ethernet, usb or SPDIF, a value is given by an amplitude at a point in time, therefore the value is dependent on time, therefore the clock of that signal forms the value of the signal. So if the clock is noisy, then the signal encoding becomes noisy …good solid systems design principles and discrete series mathematics.

Finally in systems design, system coupling is an important consideration. If the phase of the clocked signal is varying this will produce a coupled range of frequencies around the carrier in the receiver…
just like a FM transmitter.
So given these considerations, and many more, the quality of the digital transport maintains the integrity of the clocked digital signal with minimal out of band energy irrespective of streaming/digital source.

This is analogous to a preamp maintaining the source impedance for the signal for the amp, irrespective of source or attenuation into the preamp.

As you may now see the digital transport is exceedingly important just like a preamp… and of course one can usually hear this… but only buy components you enjoy a benefit from, not what others say, even Naim … it may be your adventures in hifi are absolutely met with a Sonos transport…and there is nothing wrong with that.

This is one area where Naim went to town to up the performance with their latest streamers… with the SHARC processor and the NP800 subsystem that replaced the previous legacy streamer digital transport sub systems.


Of course - but I meant into the same DAC.

That is the crux of my question!

Hi @Simon-in-Suffolk

Thank you for your comprehensive answer.

My HiFi adventures are not being satisfied by a Sonos transport (which is why I want to upgrade), but given finite resources, I want to spend my money in a way which will produce the ‘best’ (however that is defined) result of listening pleasure.

My system: Sonos Connect > Arcam irDac > Densen DM-10 > Dynaudio Contour 1.3.

There’s a story behind this as the source is obviously the weak point. I had a decent CD player until it broke. I then used (as a very temporary measure) an old iPhone so I could at least have some music. Next I bought the Arcam DAC because the iPhone was so awful; and lastly someone gave me the Sonos for free. I would never have put that system together from scratch!

I am looking to upgrade the source with a budget of around £2,000 - £2,500 (I have posed this question in the main HiFi thread) but I thought I’d ask the streamer question here.


  1. An ND5 XS 2 (I understand Naim matches well with the Densen + Dynaudio combo)
  2. A different one-box solution
  3. A replacement (having read and understood your post) streamer + DAC
  4. Keep the Sonos but buy a good DAC (money wasted if the Sonos is the weakest link?)

Anyway, thanks again for your reply.

Hi, thanks for your reply… perhaps you you have a dealer that will support a home demo… and would then see if you can audition an ND5XS2… in the Naim world that is a good streamer where Naim has focussed on sonic performance at the expense of other considerations in the product budget…
Of course that does require a preamp and amp.
An alternative is the all-in-one Uniti range,… the Atom, Star and Nova.
I wouldn’t bother with a Sonos and a good DAC… I did do this for a while, and all I can say is it works, but you may well find the resultant audio less good and enjoyable that you would want.
There are mods (DIY and commercial) out on the web to upgrade a Sonos’s transport capabilities, but can’t go into that here.

1 Like

Hi @Simon-in-Suffolk

Yes I was thinking about the ND5XS2 which is what brought me to the Naim forums in the first place.

I have a Densen DM-10 + Dynaudio Contour 1.3 which I am happy with - just want to get a source that sounds good and does them justice.

Then try to demo a ND5XS2… it sounds rather good… or NDX2 if you want the display and a greater performance.

1 Like

I will definitely give it a listen!

Thanks again @Simon-in-Suffolk :+1:

1 Like

There are a couple of used NDX2s going for about £4,200 … :thinking:

Simon,this question is also on my mind, I have a Naim Core with all my music on it and an NDS/XPSDR streamer to play the music. Is the Core digital out (SPDIF) as good as the NDS digital (SPDIF) out? In my case, i use a Chord Mscaler and TT2 DAC fed from the Naim gear.
I compared the two when i only had the TT2, and felt the NDS in the chain sounded better. Since adding the Mscaler, i have not done the comparison, but will soon. I hear a lot of talk about bridges being an upgrade, is the Mscaler considered a bridge? Since i do not use Tidal or any streaming service, i feel like i might be better off selling or trading the NDS/XPSDR in and just getting one of those Allo digi-one setups, or perhaps something from Sonore for internet radio. In reality, a dealer has made me an offer for my NDS/XPSDR in trade for a pair of speakers he has, and i am seriously considering it. Any advice appreciated as always.

I recently upgraded from a Sonos Connect to the ND5XS2. I was using the built in DAC on the Sonos to be fair but the jump in sound quality from the Sonos to the Naim is massive. Even with a separate DAC I can’t imagine the Sonos would get anywhere near the Naim. Something else to remember is that if you stream from Qobuz you get a lot of hi res albums and they really make the ND5XS2 sing, the Sonos can’t play them at all.


Change the XPS DR to 555DR, ditch the Chord and it will blow your socks off.

The NDS is a first rate source, especially with local streaming.

1 Like

I know it is good, but i can not afford a 555DR, so is the NDS (as is) digital out 9-10 K (Canadian) better than the Core digital out?

The quality of a transport would have no impact on the outcome of a DAC if two conditions were met: 1) the data transfer were error free and 2) the digital-to-analogue conversion would start only after the data transfer has completed.

The first condition is easily met in practice. The second condition could also be met easily, albeit at the expense of some convenience. Users want convenience but, above all, manufacturers want to sell expensive gear.

Thus, condition 2) is almost never met and the data transfer (via SPDIF, USB, Ethernet, etc.) and the digital-to-analogue conversion typically take place simultaneously.

It is the unavoidable interactions between these two simultaneously occurring processes that are finally responsible for the differences in the sound quality that we notice when we connect different streamers to the same DAC.

Roon and Audirvana attempt to fix cond 2 by having a fairly large buffer for the streaming data.

No, not really, I think you have missed the point. This is about out of band coupling as per my earlier post. Nothing to do with buffering which really is unlikely to have any bearing . Also there are no errors… as an error in this regard would likely sound like a static tick or momentary silences.
The transport is therefore important in terms of precision and cleanliness so as to reduce / minimise coupled artefacts.
This is analogous to mains cleanliness, or noise from poor SMPS, or the difference in different connected network components or Ethernet leads…

I would look to getting the best transport you can get. The NDS was outstanding for its day, but as far as transport / front ends things have definitely improved now, and possibly it’s weakest link.
Therefore if using its digital out as opposed to analogue out, it’s probably not the best component to have in the chain… I say you are better of using a newer transport, and with Naim I suggest that means using current NP800 based streamers.

1 Like

Do you consider the Naim Core to be a transport?

The Nds , for local streaming, is still better vs Ndx2, with both same power supply as the xpsdr. I tried and compared at dealer place. Other found the same.
For online streaming, the nds is not the best. Better choose the Ndx2.
Used as a transport only, connected to a Dac, the Nds should be better vs the Uniticore, however I have not tried. But would be very very surprised if it’s the contrary.

As transport only, connected by a Chord Dac for instance, I don’t know which one would be better: Nds or Ndx2. Only a test could demonstrate.