Crackles with Devialet Air (ethernet)

I hear cracking streaming with Roon Devialet Air (more or less once in 15 minutes), Devialet Expert 800 connected with ethernet cable to PC Windows 10.
When I look at the logfiles, I always have these lines during cracking :

07/19 11:40:25 Info: [stats] 1892mb Virtual, 687mb Physical, 401mb Managed, 1163 Handles, 46 Threads
07/19 11:40:25 Debug: [transport/devialet] NAK[131]
07/19 11:40:25 Debug: [transport/devialet] NAK[172]
07/19 11:40:26 Debug: [transport/devialet] NAK[146]
07/19 11:40:26 Debug: [transport/devialet] NAK[130]
07/19 11:40:26 Debug: [transport/devialet] NAK[66]
07/19 11:40:26 Trace: [prebuffer] status 960000/960000 (100%) @ 183/501 sec
07/19 11:40:26 Debug: [transport/devialet] NAK[50]
07/19 11:40:26 Debug: [transport/devialet] NAK[34]
07/19 11:40:26 Debug: [transport/devialet] NAK[1]
07/19 11:40:31 Trace: [prebuffer] status 960000/960000 (100%) @ 189/501 sec

I did not notice these lines : Debug: [transport/devialet] NAK[…] when there is no cracking.
Thanks for help,
best regards,

I believe @brian 's aware of these. I get them continually too, but until last night had never experienced dropouts. I had a few intermittent <1sec drops throughout an hour, but didn’t have logs open to see if they coincided.

Mine (NAKs) always occur after the stats line in the logs too, usually 7 or 8 lines of them.

I made a few tests, changing the buffer size. I played a flac 192 kHz / 24 bit album.
Buffer size = 50 ms , a dropout (music stops a short time then goes on again) after less than 3 minutes. In the log file I could see the time between “Starting playback” and the Debug: [transport/devialet] NAK[…] line (and dropout in this example, cracking noise in other ones). 2 min 43 s

Buffer = 100 ms , 3 min 04 s between Starting playback and Debug: [transport/devialet] NAK[…] line
Buffer = 500 ms , 4 min 04 s between Starting playback and Debug: [transport/devialet] NAK[…] line

I will try longer buffer sizes, but I don’t know the Default value (1000 ms was the Default value of Devialet Air 3.04).
Can someone from Roon Labs confirm the 1000 ms Default value?

It seems that with a short buffer, dropouts (or cracking noises) occur quicker.
Best regards,

Shortening buffer sizes, in almost any context–not just with AIR–will make dropouts more likely.

We provided the same set of buffer choices in Roon that Devialet provides in AIR for the sake of consistency, but I wouldn’t necessarily expect all sizes to be suitable for all networks. The very small sizes, in particular, seem very aggressive to me.

We default the buffer size to 2s over wifi and 500ms over ethernet. That is based on a balance between stability + responsiveness from our own testing on our own networks which are different from yours. If you prefer a different value, or your network requires a different value to be stable, feel free to change it.

Generally when we see NAK patterns like that, it’s a sign that something is getting overwhelmed or bottlenecked on the Expert side, and that caused the Expert to drop a lot of packets on the floor at once. “NAK” means that the Expert is requesting that Roon re-send packets that were lost. The more alarming thing is not the presence of NAK’s (these are normal), but the high counts associated with them.

Occasionally, there can be other causes for this–1000mbit to 100mbit transitions at network switches are notorious for dropping UDP packets (AIR uses UDP). Buggy switches and bad network cables (both of which are more common than you might think) can also be the culprit.

The “stats” trace has nothing to do with this–it prints every 15 seconds regardless, so it appears next to just about everything often. There is no meaningful resource usage involved in printing those stats, and they happen in a completely independent place from the AIR related code.

Finally, since you didn’t mention it, I have to bring it up :slight_smile: – please make sure that your Expert firmware is completely updated.


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Thank you for your explanations Brian!
I tried 2000 ms and could play the whole album without any dropout or noise. There was no NAK pattern in the log file.
I have a direct connection between Devialet (last firmware 10.1) and PC (with a very good ethernet cable), an external USB 3.0 drive for music files. So I thought that the only device concerned by network quality was Roon Remote (Android Tablet). Am I wrong? I don’t understand how network quality can influence a direct ethernet connection between PC and Devialet?
Best regards,

Direct connection doesn’t exclude the possibility of a poor cable, or a 100->1000 transition.

Can you share more information about the PC? CPU, RAM, does it have an SSD, gigabit ethernet port, etc?

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My PC : CPU Intel Core i5-4690S 3,2 GHz 4 cores Socket LGA1150
Motherboard : ASUS H97M-E, RAM 8 GB, SSD Hard Disk Corsair 64 GB
The ethernet port is the motherboard port Realtek® 8111GR, 1 x Gigabit LAN Controller (connected to Devialet 800, AudioQuest cable), I have another NIC connected to home network (powerline).

Before trying Roon, I used Jplay + Devialet Air 3.04
With the same hardware, I tried Buffer = 100 ms in Devialet Air 3.04 (minimum value) and never had any dropout or noise.
So I am surprised having problems with Roon.
Best regards,

Brian, this may be a red herring or coincidence in my setup, but in pretty much every log I’ve hacked through, if there’s a cluster of NAKs they’re always immediately preceded by the [stats] line. I don’t see any other pattern, at least in what I’ve looked through so far.

It’s a red herring.

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I am experiencing some crackling/distortion sounds every now and then when I listen to high res (24/192 kHz) music by using the new Devialet AIR streaming. 16/44.1 kHz is working just fine. I have used the Devialet AIR driver also previously and I think I had similar problems also with that.

I am wondering what might cause this. @support would you have any ideas?

Shortly about my setup. I am running the Roon Server on my Windows 10 desktop computer (i7 6700K, 16GB RAM, 256GB SSD for OS, and 1TB SSD for music). The Roon Server is doing some DSP (headroom -4 dB, sample rate conversion to 192 kHz (smooth, linear phase), and convolution). This computer is connected to the Apple Airport Extreme by an ethernet cable.

Then the Devialet 1000 Pro is connected to a switch (AQ-Switch-8) in an another room. Also Apple Airport Express is connected to the same switch. The Airport Express is showing following information on WIFI connection quality: speed: 300 Mb/s, RSSI: -60 dBm.

Is this problem caused by the WIFI? Unfortunately I cannot use an ethernet cable between the desktop computer and the Devialet because those are located in different rooms.

Thanks, I think it’s a good idea to try a cable temporarily. Let’s see if that helps.

Roon is causing about 1% load to the CPU so it should be just fine.

I have now connected the Devialet and the computer to the same switch with ethernet cables.

I can confirm that it works better in this way but still I have heard clicks and crackles couple of times.

Could someone from @support or perhaps @danny help on this?

Hi @Petri ----- Thank you for the report and the continued feedback. Apologies for the slow response here.

Moving forward, I am glad that you saw Brian’s post on the other thread addressing this same behavior. Indeed, some VERY good feedback there.

In terms of identifying the “culprit” here, my recommendation ALWAYS for anyone who is trying to troubleshoot potential networking issues is to always shorten the “chain of communication” to the bare minimum and see how things behave. If the issue is not present with the reconfiguration, then it’s time to start adding complexity back in and seeing where it breaks.

I noticed that you mentioned you have a switch in play. I checkout the provided link (thank you) and cannot seem to be able to identify if this switch is “managed” or “unmanaged”. My assumption is that it is “unmanaged” but can you please verify that information for me.


Just to be clear, the presence of NAK trace is not in and of itself a problem. Packet re-transmission is part of normal operation for any protocol that uses UDP–since UDP does not guarantee packet delivery. All that NAK means is that a packet needed to be resent. The NAK trace helps our technical teams put issues in context–it is not really meant to be interpreted by end users.

@support will follow up on troubleshooting any actual symptoms–but NAKs in the log are not something that needs to be fixed all by themselves.

Hi @Eric, thank you for the reply.

It is just a plug and play, 8-port gigabit switch.

I have tried earlier connecting the Apple Airport Express directly to the Devialet and I had a bit similar kind of crackles back then when streaming any high res music. There were many other issues as well. All this was happening before the Roon-AIR integration was released, so I used the Devialet AIR virtual soundcard back then.

I have found a very interesting article here :
Having changed my PC configuration recently, I forgot to change the settings of my ethernet adapter and this article helped me a lot.
I went back to buffer = 50 ms (very aggressive but very useful to do tests because problems occur quickly!).
With default settings of the Ethernet adapter, I always had dropouts in less than 5 minutes. Using Windows task manager and looking to the Ethernet perfomance, the dropouts can be seen easily : flow drops to 0 Mbit/s and then takes its normal value again (about 8 Mbit/s with a 192kHz 24 bit audio file).
I changed some basic settings of the Internet Adapter : not allowing Windows to power off the network adapter, disabling Green Ethernet, etc.)
After these changes, no more dropouts (the flow curve never dropped as before), but still some noises from time to time (buffer = 50 ms).
I tried buffer = 100 ms and played a whole album 24 bit 192 kHz without problem.(no noise, neither NAK pattern in the log file).
It would be nice if Roon technical team could tell us how to optimize the ethenet adapter settings for a connection between PC and Devialet. Clearly, it is important!
I suppose these settings are close to the recommendations I have read in the article I mentionned above, but I don’t have all the elements to be sure of it.
Have a nice day,

Hi @Petri ---- Thank you for the touching base with me, very appreciated!

You’ve mentioned the following in regard to your network topology:

Roon Server on my Windows 10 desktop computer (i7 6700K, 16GB RAM, 256GB SSD for OS, and 1TB SSD for music). This computer is connected to the Apple Airport Extreme by an ethernet cable.

Then the Devialet 1000 Pro is connected to a switch (AQ-Switch-8) in an another room. Also Apple Airport Express is connected to the same switch. The Airport Express is showing following information on WIFI connection quality: speed: 300 Mb/s, RSSI: -60 dBm.

If possible, I would highly recommend testing with the Devialet 100 Pro removed from the switch and with a direct connection to the Apple Airport Extreme. As mentioned in my previous post, whenever we are troubleshooting these types of issues it is always best to use trial and error (i.e shortening the chain of communication and adding your links back in).

I also think it is important to note that we have seen numerous issues with the Apple products in the past. Brian wrote up a very in depth post about where users can potentially get into “trouble” with certain configurations and mentioned the following:

“Poor quality or underpowered routers. The Apple AirPort Extreme is extremely bad (they seem to be exiting that business and paying little attention to the issues…I wouldn’t want one in my life). Some “cable company specials” are not great either. This technology moves over time–a first-generation 802.11n router will underperform compared to something more current, simply because the newer ones have more CPU/RAM. If at all possible, make sure your router does 802.11ac. Even if your endpoints are n-only, the bandwidth hungry phones/tablets/laptops are more likely to have ac support, which will get them out of the way a little bit.”

Let me know how it goes!

Hi Brian

Does the 1000mb to 100mb thing suggest that trying a 100mb switch might help? If you have a dedicated Roon computer and only connect that and the Devialet it shouldn’t have a negative performance impact I guess? Alternatively, what about a second Ethernet adaptor directly to the Devialet?



FWIW I use two switches between Roon Core and my Devialet. Roon (on NUC with Debian) uses one of two Gig ports on the main switch. The other Gig port connects my NAS. A 100mb port on the main switch connects to an unmanaged 100mb switch and the Devialet is connected to this with a 7m Cat5e. Both switches are HP Pro Curve.
RoonAIR has been faultless since the start. No crackles or other errors. Default buffer settings in Roon. I guess that when 1000 to 100 is handled on the same switch back plane it is optimized to work well.
As the ethernet port on the Devialet is only 100mb (I think) it might be useful to connect it to a 100mb port (or disable gigabit handshaking if the switch is manageable)

No, I don’t think so. I was reminded after mentioning the 1000->100 thing that all AIR devices are already 100mbit, so there is going to be a transition almost always. An extra switch just for the sake of it probably makes things worse, not better.

I think the next step is to figure out what makes the 3 (I think) people in this thread different from the hundreds of others using this without issue. If we can figure out the common factor, maybe we can isolate/reproduce the problem and find out what’s going on.