Streaming - To direct connect or not?

[daniel.avasilichioaei]

I'm using Intel NUC (Roon ROCK) as a streamer to Devialet Expert Pro, over Ethernet network (cable) and Roon AIR protocol.
I have two option for making this connection (please see here below image):
- Version A: via router
- Version B: direct connection
From your experience, are there any benefits to sound quality when using one of the connection modes? Or is the sound quality the same, regardless of the type of connection (A or B)?
I really appreciate your help.
   

[Jean-Marie]

To my own experience, unless stuttering, I have never been able to hear any difference due tu network topology. As you can see from my signature, my connection is not direct and goes through WiFi, a router and two plc plugs.

So I would be encline to say to go the route most convenient for you.

This being said, there are others who are perceiving differences, therefore the only safest route is to try it yourself and hear if it makes a difference to you or not.

Jean-Marie

[David A]

I have tried both methods. I've got a Nucleus+ and I can make the direct connection in one of 2 ways:

1- use the ethernet port on the Nucleus+ for the network connection and use a USB to ethernet adapter for a direct ethernet connection from the USB port on the Nucleus+ to the ethernet port on the Devialet; or

2- use the ethernet port on the Nucleus+ for the direct connection to the Devialet and use a USB to ethernet adapter for a direct ethernet connection from the USB port on the Nucleus+ for the network connection to the Nucleus+.

You can use the same approach for a NUC. You need to use manual IP addresses for both the Devialet and the port on the NUC that you connect the Devialet to. This connection method isolates the Devialet/NUC connection from network traffic. Full instructions can be found in a post from Danny Dulai of Roon in this thread:

https://community.roonlabs.com/t/bridged...us/71055/9

Danny's instructions are the second last post in the thread.

Now to your questions:

I think there is a small benefit in sound quality with the direct connection due to a slightly lower noise floor. I think the second of my 2 methods above is slightly better in sound quality than the first because you don't have the USB to ethernet adapter in the signal path to the Devialet. The problem with the second method is that you have to change the IP address of the ethernet port which was formerly your network connection and that gets a bit tricky because if you change the cable connections first, the second ethernet connection isn't set up for the network connection and the first ethernet connection, now connected to the Devialet, is not connected to the network so you end up without a network connection and then can't configure the addresses for the NUC. You need to change the IP addresses before changing the cable connections. I'm currently running with the first of my 2 methods above which is the one Danny Dulai describes. It's a lot easier to work with when it comes to network connections because the single ethernet port on my Nucleus+ remains the network connection for the Nucleus+ and all I have to do to swap between a normal networked connection and the direct connection is to change the config file for the Devialet and change the cable connections back to my ethernet switch.

The reason I'm using the first method above, even though I think the second method gives slightly better sound quality, is because I had been using the second method and wanted to change my config file slightly for the Devialet and ran into a problem because the SD card reader in the Devialet stopped working. I ended up having to revert to factory config and having to reconfigure the IP addresses for the 2 ethernet connections to the Nucleus+ which was a bit of a nuisance. I had to send the Devialet back to France for repair and got it back a few weeks ago. Initially I set it up with a normal network connection but I have just gone back to the direct connection using the first method today, simply because it's a lot simpler dealing with problems when the first method is used.

There is another issue, the problem we currently have with gigabit ethernet connections to the Deviaelet if you're using Roon RAAT as i am. If you use the first method I outlined above, you've got a gigabit connection to the Devialet. If you use the second method you will have a gigabit connection if you use a USB3 to ethernet adapter and you will have a 100 connection if you use a USB2 to ethernet adapter. Using the USB2 to ethernet adapter for the ethernet connection to the Devialet should avoid the current problem. I have managed to trigger the problem with a USB3 to ethernet adapter, and also with the direct connection made to the Devialet from the ethernet port of my Nucleus+ but it did not occur immediately and it can take some time to show up. YMMV but this shouldn't be a problem for you since you said you're using Roon AIR.

Is it worth swapping to the direct connection method? As I said, I think there is a small improvement in sound quality. I've been extremely happy with the sound quality I get using the network connection and I went back to the direct connection method today to check my impressions. I still think there's a small improvement and it's nice to have but it isn't a problem living without it. It can be a little tricky setting up the direct connection, especially if you use the second method where you're connecting the Devialet directly to the single ethernet port of a Nucleus rather than to one of the USB ports via an adapter and I do wonder whether that connection is worth the extra work involved and the problems I had when I had to revert to a network connection with the Devialet when its SD card reader failed so I would recommend the first connection method over the second if you want to try the direct connection, purely because it's easier to revert to a network connection if you have to.

Don't expect a big gain in sound quality. The change is subtle, just like the gain you get with any small reduction in noise level.

[David A]

1 additional point: If you do go the direct ethernet connection route you lose the wired network connection for the Devialet. That currently isn't a problem if you do all of your streaming via Roon but it may become a problem in the future if Devialet introduce additional functionality via network connection. If you use another streaming source besides Roon you will need to use wifi for that source. With the direct connection the Devialet is completely unable to connect to your network via ethernet and there apparently is no way around that restriction. If you want to use other streaming sources besides Roon and you want to use ethernet for them, stick with the network connection and forget about the direct connection method.

[daniel.avasilichioaei]

@David A

Thank you for very detailed answer.
Currently I am using direct connection with your second method. Setting up the direct connection was easy.
I also believe that there's a small improvement over your first method, and also over connection via router. But, I cannot make a side by side comparison, so it may be just Placebo...

[Confused]

@David A - Out of interest, what makes you think direct connection provides a slightly lower noise floor? If anything, I would have thought that a router (or a switch) would help to insulate the Devialet from the noise of the computer (NUC)? Or to put it another way, if you want to reduce noise, the last thing you want to do is attach a complex and electrically noisy NUC direct to a Devialet.

To be clear, I am not disputing that this method of connection can provide benefits to sound quality. There is an extensive thread on Audiophile Style (Computer Audiophile) that has covered this topic. Many people have posted about clear audible benefits from a direct ethernet connection, subjectively it does indeed appear to work. However, there appears to be no technical conclusion from anyone as to why this should be. Lots of speculation about clock phase noise, latency, and other theories, but nothing conclusive.

[David A]

@Confused ,

Answer 1: Don't ask me, I know nothing about networking. I often joke that a lot of things in audio work because of voodoo and things like how many chickens you sacrifice and whether you do it at the dark of the moon all play a part. There's no way I can give you a technical explanation, much less one that's likely to be convincing.

Answer 2: You say that you would have thought that a router or switch would help to insulate the Devialet from the noise of the NUC. What kind of noise are we talking about? My understanding is that there's no noise added to the actual digital signal but that electrical noise gets carried by the connection and can be transmitted to the circuits of the Devialet. Routers/switches are supposedly noisy, that's one of the reasons that people buy things like audiophile grade ethernet switches and use ethernet to optical and optical to ethernet connections to provide a level of isolation that a router or switch doesn't provide. I've got no idea whether or not those claims are correct but it seems there are a lot of people who accept that they are correct. The switch I've been using isn't audiophile grade and I've also been using the normal switch mode power supply with it, not an LPS.

Basically, a slightly lower noise floor is the only thing I can think of which could make a difference. The improvement I hear is an increase in clarity and definition, the sort of thing you notice when the noise floor drops for some reason and that also inclines me to the lower noise floor explanation. If I am right and I do hear a difference, the explanation for the difference could be something else.

As I said, I think it's a small difference in this case but I think there is a difference and it is an improvement. Before I tried the method in Danny Dulai's instructions I tried a couple of different settings for the manual IP addresses, hit and miss attempts at getting a direct connection to work because I couldn't find any clear instructions about how to do it. The first such attempt worked with some improvement but also some aspects of the sound were slightly worse, the second method I tried was better without the problems of the first. Danny's settings were the third lot of settings I tried and they worked better for me than either of my 2 attempts so I now recommend his approach. I'll add that he said in the thread I provided a link for that he isn't certain that there will be a difference and that he doesn't recommend the approach so it's definitely one of those things that people need to try for themselves and see what they think.

In the end it all comes down to the fact that we can make a direct connection work. We really can't eliminate a router, after all the NUC/Nucleus needs a network connection so it's going to connect back to a router somewhere but we can avoid having a router or switch between the NUC/Nucleus and the Devialet and depending on how your network is set up that may remove one network device which is a potential source of noise from your system. In my case, it lets me remove the switch that both my Nucleus+ and Devialet connected to. It also results in the NUC/Nucleus to Devialet connection only carrying traffic related to the actual music stream since all traffic between the NUC/Nucleus related to the internet connection that Roon uses goes via the server's network connection and isn't carried by the connection carrying the music stream. Whether or not the direct connection delivers an improvement in sound quality and how much of an improvement it makes is up to the user to decide, along with whether they think whatever improvement they get justifies putting up with the process required to get it working and the fact that they lose a wired network connection to the Devialet.

[K4680]

Hello, I have tried several configurations during the year and now have the following setup (see sheet 2):

1. The switch is directly on the system
2. No LAN cable is longer than 0.7m (except for the feed line)
3. All devices are supplied with LPS
4. Connection with 1GBit/s

Compared to the previous wiring (sheet 4), the little noise has disappeared and it sounds better for me. Between the USB and the Lan connection I could not find great differences. I stay with the LAN connection and Roon RAAT.

[daniel.avasilichioaei]

The “translation” of my question is what is worst for sound quality: the extra work/noise generated by the second USB network card inside NUC (version B), or the extra devices/noise generated by router (version B)?

[David A]

The “translation” of my question is what is worst for sound quality: the extra work/noise generated by the second USB network card inside NUC (version B), or the extra devices/noise generated by router (version B)?

I can't answer that question. Surely it would depend in part on the quality of the second network card vs the quality of the router so, given a different system with different network card and router, the answer might be different. Also, when we talk about sound quality we're talking about subjective impressions. One person's sound quality can be another's nightmare which is why we have people liking vastly different sounding speakers and amplifiers.

With both setups you've got the same source, the same amplifier, you're using the same input on the Devialet and the same speakers. The major determinants of the quality and character of the sound are unchanged. You aren't going to change the character of the sound, you're changing something that may result in a slight difference in some characteristic of the signal transmitted to the Devialet which has no affect on the data content of the signal, the bits themselves are going to remain the same. From my experience any change will be a small change in areas like clarity and definition, it's not going to be a change in the character of the sound. Don't forget that in that thread on the Roon site to which I provided a link, Danny Dulai of Roon states that he's uncertain that using a direct connection will make a difference and that he doesn't recommend doing so, he's merely suggesting what he thinks would be the way to do so.

I don't think anyone is going to be able to give you an answer to your question, especially given that we're discussing something that we all make our own subjective judgements about. All I can suggest is that you try it for yourself and see what you think, provided the process of doing it isn't an issue for you and losing the wired network connection to the Devialet isn't a problem for you. Even if you had the same gear as me I'd still say the same thing. Don't go into this sort of change expecting big differences, go into it with an open mind and a sense of inquiry in order to find out whether it makes a difference for you, not with the expectation of getting a particular difference. If you go into it expecting a particular result I doubt you'll get the result you expect. You may get a result you like, I did, but that isn't guaranteed.