Local endpoint no longer appears in Settings>Audio
In Settings>Audio I should see and be able to enable a local usb-connected Astel&Kern Acro 1000, a headphone/monitor amp and DAC. It appears in my audio settings, plays directly from my iMac M3, and uses to appear in Audio settings as a local endpoint. It disappeared about 2 weeks ago. In addition, when I select Settings>Audio, the screen flickers continuously, behavior I have not experienced previously. This setup has been quite stable for a very long time.
Do you happen to have any antivirus, VPNs or firewalls that may be blocking Roon/RAATServer from operating properly? One other troubleshooting suggestion would be to perform a RAATServer refesh on the affected PC (which doesn’t show the needed devices).
You can generate a new RAATServer instance on your device by following these instructions, but please be aware that this will reset your Roon Settings → Audio Tab to factory settings and I would advise making a backup of any custom DSP settings you have:
Thanks for these suggestions.
No VPN running.
Refreshed the RAATServer but the local usb DAC does not appear, and the screen still flickers continuously.
What’s next?
Thanks for the update, and sorry to hear your issues persist.
To confirm, have you tested both different cables, as well as different ports?
The screen flickering likely doesn’t have anything to do with your DAC issues - does the screen only flicker when viewing your Roon Settings>Audio page?
I’d also check your cable connections around your screen/monitor. Test out different cables and ports here as well if possible.
What happens if you temporarily disable your Mac firewall? Any changes there?
What happens if you plug the DAC into a different machine? Are you able to see it properly?
The screen only flickers on Roon Settings>Audio page. Not on any other Roon pane or any other view ever experienced on this computer. Cables and ports are not the issue here.
The screen appears to flicker between the view that includes the local endpoints that should be available, and the view I captured in the screenshot without them. I can see the “This Mac” icon when it flickers.
As for plugging the DAC in elsewhere. I will try that, but the DAC worked just fine where it is until a week or so ago - I cannot remember how that accords with the last Roon update.
Since some time has passed, we wanted to follow up on this thread to see how things are going?
Have you review your Audio/Midi settings on the Mac?
Navigate to Applications > Utilities > Audio MIDI Setup. Ensure that your DAC is recognized and configured correctly. If it’s not listed, macOS isn’t detecting the device, which could indicate a hardware issue.
It’s also unclear if you’ve tested different cables / ports - please do so and let us know if there’s any change in behavior.
Have you reviewed your Mac firewall settings?
Go to System Settings > Network > Firewall. Temporarily disable the firewall to see if it’s blocking Roon’s access to connected devices.
Privacy Settings: In System Settings > Privacy & Security, ensure Roon has the necessary permissions to access external devices.
If none of the above help, lets perform a Roon database refersh to see if that helps:
• The A&K Acro is recognized and properly configured in Audio MIDI Setup
• different cables and port have been tested.
• A MacBook M4 tested with 2 different A&K Acro amp/dacs has the same issue
• Roon has local network access
• I have tried a Roon data base refresh
• I am updating my internet speed and bandwidth tomorrow, so I will report back if that was the issue
There are a few due diligence items that we need to perform to ensure instability isn’t caused by a build mismatch.
We see two RoonServers active in this setup, one on Build 1490, and one on the most recent build, 1496. Both have been active in the last two days, and they have different library counts, so we can’t ensure that these are distinct machines or just the server reinstall you performed.
Not all of the Mac Remotes are updated to the most recent build. There’s an Intel Mac that has recently pinged our servers on an older release, but the other Silicon Macs are on the most recent build.
Having covered that, we want to request a manual logset from the M3 and M4 Macs where these endpoints are failing to register with RAATServer via the loopback.
Please use the directions found here to find the Roon folder on the M3 machine in particular. That folder should contain a logs folder. Zip (compress) that folder and send it to our Logs Uploader Service and let us know after, thanks!
I recommend opening Roon with this USB DAC connected and using Terminal to restart the coreaudio daemon.
Open Terminal and enter: sudo killall coreaudiod
You’ll momentarily lose local audio across devices until coreaudio re-engages with any outputs.
Additionally, in your WiFi settings on the affected Macs, make sure you have a Fixed, not a Rotating, WiFi Address assigned. If the MAC address has been randomized, RoonServer might temporarily lose the RAATServer instance in those computers over the network.
Let us know if this helps. We’ll watch for your response. Thanks!
Thanks for the checklist. I restarted the core audio daemon and it had no effect on the problem. Also, it is interesting that the older Intel Mac is on the older release, because that test did not have the problem I am facing on the M4 MacBook Pro and the M3 iMac.
One more wrinkle. When Roon is up on the M3 iMac, the connection to the SonicTransporter i7 cycles off and back on every 5 minutes or so and then returns to normal. Screenshots attached.
My apologies if this has been glazed over, but what happens if you temporarily move one of your Macs to run as your Roon Server instead of your Sonic Transporter? Is there any difference in your audio device availability in this case?
Interesting question. Seeing up the iMac as a Roon Server I can see and acted the local speakers as an endpoint and the flicker does not occur. I tried moving the Sonic Transporter to other locations = other switches, and the same one the iMac is on, but the same issue appeared.
So what does this mean? My only point of reference is that this took place after the first 2025 Roon upadate…
Thanks for the follow-up! Let’s focus on the Sonic Transporter for now - are you able to perform a factory reset or fresh re-install on the machine? That would the best next step here.
After that, if you’re still seeing issues, it would be best to get in touch with ST support directly, as they’ll be able to review a more in-depth diagnostic report on the hardware of the machine itself.
You can get in touch with their support directly by heading to their site (which I’ll link below) and clicking the green ‘Contact Us’ tab on the bottom right of the screen:
I have not changed the SonicTransporter, other than keeping up the software to date. It went in to be upgraded to v 2.9 about 6 month ago.
2 more recent tests lead me to question whether the problem is the ST:
When I set up the iMac as a Roon server, the iMac works fine but other remote MacOS and iOS devices can’t connect to it as a server. The message stays on “connecting to…”
I also set up an older Mac mini as a Roon Server. I works fine sending music to Roon endpoints, and other devices can see and connect to it, but the MacOS devices (not the iOS devices) have the same local problem and flicker as the SonicTransporter.
This is a good piece of information to share - thank you! I agree the issue may not be pinned to the ST itself. Are you using the same display/monitor when you’re swapping your server machines?
When you setup your older Mac mini, did you perform a completely fresh install? Lets perform a server database refresh as a last step in terms of Roon, Roon Server, and RAAT Server:
I performed the test with the Mac Mini (intel 4 core) as you suggested. Set up as a Roon server with newly downloaded software and checked for the current version. Both iOS and MacOS devices can connect to it and direct music to remote endpoints.
The result shows the same problem: both MacOS devices (iMac M3 and MacBook Pro M4 connected by ethernet) cannot display a local endpoint (ethernet-transport-DAC) and the pane flickers while it is viewed.
I also tried the Audio setup on an iMac M3 and MacBook Pro M4 connected by ethernet to different switches - on the same switch as the Mac Mini server and another part of the house.
Seems like either there is something wrong with the AT&T network or with the ROON build?
Thank you for all the additional troubleshooting so far!
An interesting theory - no one has been able to reproduce this issue in house, and we’re not seeing any additional reports of the flickering across community, so for now it seems like the issue is local to your setup.
Based on the machines you’ve tested with so far, it’s safe to assume you’re not using the same monitor - but I wanted to triple-check on this aspect.
If you could, please record a video of the issue, and upload to our media uploader below:
Lastly, the issue seems tied to the Acro 1000 specifically. Can you please check the firmware version, and perhaps perform a fresh reinstall of the most recent firmware on the device? It may be worth getting in touch with the manufacturer directly for the above steps.
