Repeated dropouts


I set up Roon for the first time yesterday with a Sonic Transporter as Roon core accessing the library on a Synology NAS, and a Sonore Microrendu as endpoint feeding a Chord Hugo TT DAC. I am controlling Roon from a Mac connected to the network.

I get short dropouts (one second long or thereabouts) every few minutes. It seems Roon loses contact with the endpoint. Occasionally when sound comes back there is distortion and noise for a few seconds. Rarely in these occurrences, when the noise stops Roon skips to the next track. When normal play resumes everything seems fine (sound quality is excellent). In certain moments, the dropouts/noise occur more frequently (less than a minute between occurrences)

In one occurrence, Roon lost contact with the library and couldn’t find it again. After restarting Roon on the Mac and on the Roon server and restarting the router, it reconnected.

The Sonic Transporter, NAS, and Microrendu are connected via Ethernet through a Cisco switch (1,5 meter cat 7 cables). The switch is connected to the router via a cat5 cable (3 meters or so). No wifi.

The NAS is set up for SMB3. AFP is turned off. The NAS was mounted in Roon.
I also had a dropout at every track change with a different sampling frequency, but increasing the rate switching delay seems to have fixed that.

The library has 67000 tracks and I noticed at one point that the Background Audio Analysis was stuck. Changing the speed to Fast restarted it but the process is quite slow (as I write this it is analyzing 447 with 66000 to go). Could this be the issue? I read somewhere of a bug related to this in the latest Linux build (V1.2 build 142, which I am using). It seems once the analysis is complete the problem goes away. Is this correct, and if so, is there a way to speed up the process?

Any other suggestions would be much appreciated. The situation is fairly intolerable…


On a large library, Roon can take awhile to analyze the music, depending on cpu/memory/network speed. I wouldn’t use Roon until the analysis is done.

To see if this is the issue, you can go to Settings/Setup and turn “Background Audio Analysis Speed” to OFF. Also, turn “On Demand Audio Analysis Speed” to OFF. Keep in mind that you won’t get the waveform on the playback bar, you can’t do crossfade or volume normalisation; but, it will eliminate the audio analysis as a cause for your dropouts.

If it works, then turn on the “On Demand Audio Analysis Speed” to normal and see how it acts. This will only analyze the music once it is played. I would then set aside a weekend that you won’t use Roon to turn the analysis of the whole library on.

As for the analysis getting stuck. It can stall out if it finds files which it considers damaged or corrupt.

The only way to speed up the analysis is to set it to Fast in settings and leave overnight :slight_smile:

As for the main complaint:

  1. Launch Roon
  2. Go to Setup tab in Settings
  3. Disable Background Audio Analysis and On-Demand Audio Analysis
  4. Try to reproduce the issue

Second test is

  1. Store few tracks on the ST built-in drive
  2. Add those tracks to Roon using Watched folder
  3. Try to reproduce the issue using recently added tracks

Also make sure that you aren’t using Jumbo packets (check the NAS and Switch settings), make sure that you aren’t using port aggregation for your NAS.


Waves at @vova. Jinx!

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Thanks very much for your suggestions

I have disabled the analysis in both background and on-demand mode - I have been listening for almost 15 minutes and I have had two short dropouts. So the frequency of the problem seems reduced so far, but not eliminated.

I am using a Cisco SGD100-08, which is unmanaged and has no configuration. On my Sinology 1515+, Adaptive Load Balancing is on and Link Aggregation is off (I didn’t find a setting for Port aggregation - I assume it is the same thing). I will try turning off load balancing as well.


I’m afraid the problem has been reduced but not solved. Still get dropouts every few minutes.

Will try the second test tomorrow

Thanks. Let us know the results of the second test.


The second test did not eliminate the problem.

I did the following:
I copied 4 hd music files to the Sonic Transporter’s hard drive. I turned off both types of analysis and played the files. I left the NAS connected and powered up and made sure Roon was playing the file on the ST (it selected that file by default, also I monitored the NAS and there was essentially zero network activity while playing).

During the first file, I got 8 dropouts in 50 minutes of playing time. (In one case, but it may have been a coincidence, the dropout occurred when I clicked on the Album Editor symbol. I tried this again a few times and it did not cause a dropout.) One of the dropouts also resulted in a few seconds of noise when sound came back, the others were “clean.”
During the second file on the ST, 6 dropouts in 46 minutes. One with noise and skipping to the next track

I then reactivated analysis in both modes just to see the difference and started to play the third file on the ST. 6 dropouts in about 25 minutes of play so far, 4 with noise.

On a separate note, I am monitoring progress of the analysis which I continued overnight and when not testing. It is very slow, processing about 220 files an hour. Is this normal? With about 65k files to go, that means 13 days of continuous processing - well beyond the end of my trial period, by the way.

I understand the ST was designed to be used as a Roon server so it doesn’t seem attributable to insufficient processing power.

I hope you can help me solve this problem



For my trial I setup a test system with only a small (5,000 file) subset of my music. I wanted to get a feel for the software in a controlled environment.

To me it sounds like it is the sonic transporter and I would suggest testing this by turning off the sonic transporter; setting the mac as your Core with those same HD files copied to its internal hard drive.

If it works by playing an hour uninterrupted, I would then copy the test grouping to a location on your NAS and verify that the MAC/NAS also worked.



Any thoughts on how to proceed following my feedback on the test you suggested?

I saw Rugby’s suggestion but is it possible to switch to another machine core and restart during the trial? Would I lose the analysis done so far on the current machine, which has been painfully slow (see below)? I hesitate to “start over” and I wonder if there is a simpler way to proceed with troubleshooting.

By the way, I have let the system run continuously with the analysis over the last 30 hours, without playing anything (I was actually away during this time). It has done an average of 239 tracks per hour. Can you tell me whether this is normal? I have been searching but found no reference to the expected analysis times. If the analysis is slower than expected, as I suspect, it would seem to suggest that there is another issue that needs resolving (perhaps linked to the main dropout issue if there is a performance problem somewhere)

I appreciate your continuing help on this


Hello @Marco_Castaldo,

Rugby’s suggestion sounds tough, but it’s the only way how “overloaded hardware” can be eliminated from our list of suspects.

As for now, let’s first finish the tests which will exclude “network instability”:

  • Can you try to connect Chord Hugo TT DAC directly to the SonicTransporter and playback those 4 local tracks again. To see if dropouts still persist.
  • Also, do you get similar dropouts in case of playback to the zones on your Mac ?

Regarding analysis, it mostly depends on the CPU of the device where Roon Core is installed. But general idea is that in “Normal” mode Roon uses 1/3 of a CPU core in order to minimize disruption/heat/fan noise. “Fast” tries to use 1 full CPU core for analysis, assuming your storage devices and network can keep up. But to me 239 sounds reasonable for Normal mode.


Hi @Marco_Castaldo

I don’t believe I can connect the DAC directly to the Sonic Transporter: I understand that it streams music to the network only and that the USB connections are only for external discs.

I just carried out the second test as follows: I enabled the MAC’s built-in output and played a DSD64 track. I heard some background clicking below the music (possibly an issue with the MAC’s decoding) but, more importantly, 3 minutes into the track I had a dropout and a skip to the next track. I downloaded the ST’s Roon app logs if you would like to see them. They clearly show the dropouts and the termination of the track, but I don’t have the knowledge to further interpret them.

One note: the MAC is not connected to the switch with the NAS, Sonic Transporter and Microrendu. It is connected directly to the modem/router (the aforementioned switch is also connected directly to the same modem/router.

In the meantime I have been reviewing my network setup and am hypothesizing that there may be an issue with the router which is built-in to my ISP’s modem. I ordered a Cisco wired router and plan to redesign my network so the Cisco will be doing the routing and not the ISP’s modem (having read that some don’t recommend my current setup). The modem will arrive thursday and I probably won’t be able to work on the network until the weekend.

In the meantime let me know if you have any thoughts based on the results of the test. I also have the ST’s and the Microrendu’s logs from a previous listening session showing the dropouts.

Thanks for your feedback on the analysis. I will let the system chug away with the analysis. Given that my trial expires on the 14th it would be nice to get an extension, unless the dropout issue is sorted before then.

Thanks again for your support


Hi @vova

I addressed the previous message with the results of the test to myself by mistake. Please review it when you have a chance



Hi @vova

I have moved forward with testing and have achieved interesting results:

First of all, I modified my network by inserting a Cisco wired router and an additional switch downstream of the ISP’s modem/router to eliminate any negative effects due to the latter. One cable from the ISP modem to the new router, one cable from the new router to the new switch, to which I connected the rest of my network and the switch which connects NAS, Microrendu and Sonic Transporter. This last part of the network is the same as before. The problem did not go away: dropouts every 3 to 5 minutes of playing.

Then I decided to use different software to see if it there is a hardware problem with my NAS/Sonic Transporter/Microrendu. I switched from Roonready to Squeezelite on the Microrendu and from Roon Server to Squeezebox Server on the Sonic Transporter.

First I played a record which in a previous test I had copied to the Sonic Transporter’s internal SSD. Played for over half an hour and not a single dropout. After that I started to played music from the NAS. About a half hour of play and still going, not a single dropout.

At this stage, unless I missed something, I am tempted to conclude that there is a compatibility problem between my setup and Roon.

What do you think?


Hello @Marco_Castaldo,

Thanks for the tests. But I still think we should try to simplify your network setup and make sure that multiple network gear isn’t causing those problems. You can try to connect SonicTransporter and Microrendu to the same unmanaged Cisco switch, make sure that router has assigned IP’s to both devices (in case DHCP is used) then disconnect the switch from the router (so it would be an isolated environment) and try to reproduce the issue again.

In case the mentioned above test will also result in dropouts, I would recommend to try to switch Roon Core to your Mac.


Hi @vova

Before I read your latest I decided to restart my Roon installation from scratch on my Mac, to exclude the Sonic Transporter from the diagnosis. First of all, I deleted and reloaded Roon Server on the Sonic Transporter and then shut it down. I connected the MAC directly to the same switch serving the Sonic Transporter, the NAS and the Microrendu.

I setup a new Core running on the Mac with a small library of high res music from a watched folder on the MAC’s internal HD and a watched folder on the NAS.

Test 1: Output through Mac’s audio (earphone) output, playing music on the Mac’s internal folder. No dropouts after 10 minutes or so (not much point in testing this further)

Test 2: Output through Mac’s audio (earphone) output, playing a 24/192 Flac file on the NAS. No dropouts after 25 minutes. I think we can exclude a problem at the NAS level and in the network hardware and connections, at least in this configuration.

Test 3: Output through the Microrendu connected to the Chord Hugo TT Dac and a 24/192 Flac file from the NAS. Back to the original configuration, but excluding the Sonic Transporter altogether. No dropouts in this configuration either (about 25 minutes and going).

Should I try going back to the previous configuration and perform the network isolation test or do you have other ideas based on this new information.



I think you’ve discovered your issue.

Now I need the solution…


I wanted to post the Roonserver and Roonready diagnostics showing the dropouts in the original configuration but I note only image files are allowed and there are several pages.

If you want the logs please let me know how I can send you a Word or Pdf file