I like the way @David A started off by stating "I think you'll find a lot of different answers to your questions", because I think he is absolutely right on this one.
I with my previous D240/D250/D800 (Pre Pro), I tried many things via Ethernet, USB, S/PDIF. First to say that I was always happy with the sound quality via Ethernet, although in the early days of AIR this was far from trouble free. I never found anything that I preferred via USB, it was always a touch softer and lost something to my ears, but refer to the opening statement here, I know that there are some that will disagree with this.
For me, the very best results I have obtained from either the early models or the Pro have been via AES/EBU (S/PDIF). David mentions above that ethernet should be less jitter-prone than a coaxial connection. He is right of course, essentially with Ethernet any concerns regarding jitter from the source is eliminated. It is not quite that simple though I think. What I have found is that via AES/EBU / S/PDIF, the source really matters. The end result is that with a not so good source, feeding the Devialet via S/PDIF will provide inferior results versus pretty much anything via Ethernet. But with a very good AES/EBU source, it is possible to get better results than Ethernet. In the early days of the Expert range there were quite a few of us on this forum feeding the Expert with a Mutec MC3+USB, and getting results that sounded better, and were a lot more stable than AIR Ethernet.
So to my ears at least, S/PDIF or AES/EBU is the way to go, but you do need a decent source. Yes, jitter from the source becomes an issue here. With S/PDIF the source actually provides the audio clock that needs to be extracted by the receiving device. But get a source that performs well in this regard and decent sound should result.
Did anyone mention rabbit holes?
Writing this makes me think about the iFi Zen Stream that I mentioned in another thread. The measurements of this device indicate that it has very low noise and jitter. So far I have only listened to the thing via my Mutec MC3+USB / REF10. Maybe it will perform decently feeding the Devialet direct? When I get some time I'll give this a try.
As for Roon, I use Roon for a number of reasons. Some aspects of it I like, other aspects annoy me greatly. I terms of sound quality, I do prefer Roon + HQPlayer for Ethernet streaming, although this becomes an easier option if you have a HQPlayer / NAA type endpoint, with a Devialet alone RAAT or Roon integrated AIR are the only practical options.
One last observation. About a year and a half ago I changed from a fairly basic PC to a far more powerful i9900K machine with Nvidia graphics and all the rest of it. For a while I had both machines set up, and I could easily switch from streaming from the old PC or the new. Would the more powerful machine sound better, or perhaps worse as it is more complex and electrically noisy device? Both machines were running HQPlayer, so the playback software was identical, between the two I could not discern any difference whatsoever.
EDIT: I have just noticed that the OP mentions Roon's DSP capabilities. Recently I have started running Focus Fidelity Filter Designer convolutions in Roon. Getting this set up and working correctly is not the easiest of things, just getting the measurements done correctly is full of perils, but for me the end result is superb, far exceeding the kind of improvements you might get from one source or another. This kind of thing will be very system and room dependent, but I could not be more pleased with the improvement it has made in my case.
I with my previous D240/D250/D800 (Pre Pro), I tried many things via Ethernet, USB, S/PDIF. First to say that I was always happy with the sound quality via Ethernet, although in the early days of AIR this was far from trouble free. I never found anything that I preferred via USB, it was always a touch softer and lost something to my ears, but refer to the opening statement here, I know that there are some that will disagree with this.
For me, the very best results I have obtained from either the early models or the Pro have been via AES/EBU (S/PDIF). David mentions above that ethernet should be less jitter-prone than a coaxial connection. He is right of course, essentially with Ethernet any concerns regarding jitter from the source is eliminated. It is not quite that simple though I think. What I have found is that via AES/EBU / S/PDIF, the source really matters. The end result is that with a not so good source, feeding the Devialet via S/PDIF will provide inferior results versus pretty much anything via Ethernet. But with a very good AES/EBU source, it is possible to get better results than Ethernet. In the early days of the Expert range there were quite a few of us on this forum feeding the Expert with a Mutec MC3+USB, and getting results that sounded better, and were a lot more stable than AIR Ethernet.
So to my ears at least, S/PDIF or AES/EBU is the way to go, but you do need a decent source. Yes, jitter from the source becomes an issue here. With S/PDIF the source actually provides the audio clock that needs to be extracted by the receiving device. But get a source that performs well in this regard and decent sound should result.
Did anyone mention rabbit holes?
Writing this makes me think about the iFi Zen Stream that I mentioned in another thread. The measurements of this device indicate that it has very low noise and jitter. So far I have only listened to the thing via my Mutec MC3+USB / REF10. Maybe it will perform decently feeding the Devialet direct? When I get some time I'll give this a try.
As for Roon, I use Roon for a number of reasons. Some aspects of it I like, other aspects annoy me greatly. I terms of sound quality, I do prefer Roon + HQPlayer for Ethernet streaming, although this becomes an easier option if you have a HQPlayer / NAA type endpoint, with a Devialet alone RAAT or Roon integrated AIR are the only practical options.
One last observation. About a year and a half ago I changed from a fairly basic PC to a far more powerful i9900K machine with Nvidia graphics and all the rest of it. For a while I had both machines set up, and I could easily switch from streaming from the old PC or the new. Would the more powerful machine sound better, or perhaps worse as it is more complex and electrically noisy device? Both machines were running HQPlayer, so the playback software was identical, between the two I could not discern any difference whatsoever.
EDIT: I have just noticed that the OP mentions Roon's DSP capabilities. Recently I have started running Focus Fidelity Filter Designer convolutions in Roon. Getting this set up and working correctly is not the easiest of things, just getting the measurements done correctly is full of perils, but for me the end result is superb, far exceeding the kind of improvements you might get from one source or another. This kind of thing will be very system and room dependent, but I could not be more pleased with the improvement it has made in my case.
1000 Pro - KEF Blade - iFi Zen Stream - Mutec REF10 - MC3+USB - Pro-Ject Signature 12
