MacOS 26.4 - Playback failure after sample rate change (ref#XPA6CK)

Support
23

Thanks for full diagnostics here:-)

24

No problem at all @Wouter_Kolkman, since a few days have passed we wanted to check in and see if the above was helpful?

We’ll be monitoring for your reply, thank you! :+1:

25

Just surprised that the drop occurs when changing albums. No drops during playback.

26

Hi @Wouter_Kolkman,

In order to proceed from here, we’ll need to compare RAATServer logs from the RoonBridge machine directly with RoonServer logs. Our diagnostic servers can access the latter, but we’ll need to request you to kindly upload the RAATServer logs directly to our servers.

At your convenience, please take the following steps on the RoonBridge Mac:

  1. Open Finder and click Go in the top bar
  2. Hold down the Option key (or Alt)(⌥) to unhide the Library folder
  3. Click the Library folder 
  4. Look for the RAATServer folder and locate the Logs folder within
  5. Compress (zip) the logs folder
  6. [url=https://workdrive.zohoexternal.com/collection/8i5239cc05950ac07456889838d9319545a82/external]Upload it here[/url] to our secure servers.
Thank you!
27

Hey, @Wouter_Kolkman,

Just checking in on this. Were you able to zip up the RAATServer Logs from the RoonBridge Mac and upload them to our secure server so we can compare them with the RoonServer logs? If anything about finding the Library folder or the RAATServer Logs folder on that Mac was unclear, let us know and we can walk through it again, thanks.

28

I uploaded the logs a couple of days ago:-)

29

Hey @Wouter_Kolkman,

Thanks for sending those over! We can see a definitive pattern: every single DEVICE_INIT_FAILED occurs exactly 7–8 seconds after starting output, on both subnets, regardless of network path. That fixed ~8-second delay is a CoreAudio start timeout, the DAC simply doesn’t acknowledge the start within the window. This is a local USB/CoreAudio device-init failure, not a network problem.

The real failure signature. Every playback failure in these logs is the same event:

[output/coreaudio] setup: format is pcm 96000/24/2 ← new track / sample-rate change
starting output
(≈8 seconds later)
Warn: Error in AudioOutputUnitStart: 35 (0x23)
setup failed: RAAT__OUTPUT_PLUGIN_STATUS_DEVICE_INIT_FAILED

I was incorrect in my prior reply, you have my apologies there! Let’s see if the following help:

You currently have resync delay at 0 ms. The failure is at the start of the output unit, where the DAC needs a moment to lock after a rate change, so 0 ms is the worst setting for this particular failure, even though it was suggested earlier in the thread.

In Roon: Settings → Audio → the Denafrips → gear → Device setup → set Resync Delay to 1000–3000 ms. Test with the alternating-rate playlist from step 1. This gives the DAC time to settle its clock before CoreAudio tries to start the unit.

With that, the logs show dsd_mode=dop and MQA USB support enabled. Rate-change re-inits are more fragile when the driver is juggling format-capability negotiation:

  • In the same device setup screen, try Integer Mode on (you noted toggling it "wakes" the device, running with it on may avoid the failed state entirely).
  • If you don't play DSD, set DSD playback strategy to PCM (or DoP→Off) to simplify the handshake.
  • Test each change independently so you know which one helped.

Additionally, CoreAudio error 35 at start is frequently a USB enumeration/power timing issue:

  • Move the DAC to a different USB port directly on the Mac mini (not a hub).
  • Swap the USB cable.
  • If anything sits between the Mac and DAC (hub, switch, regenerator), remove it for the test.

We’ll be monitoring for your reply, thank you! :raising_hands:

30

Hey @Wouter_Kolkman,

Just checking in on this. Were you able to try the device setup changes we mentioned, especially raising Resync Delay to around 1000 to 3000 ms, then testing Integer Mode and, if needed, switching DSD playback strategy to PCM or DoP off? We also asked whether moving the DAC to a different direct USB port on the Mac mini, swapping the USB cable, or removing any hub or switch in between made any difference, so let us know what you found if you have any updates to share, thanks!

31

Changed the sync delay - not solved yet. Will try different USB port next. They are supposed to becequal, but I know they are not.

32

Changed to a different USB port - no difference

33

Hi @Wouter_Kolkman,

Thanks for the update. There are still a few outstanding troubleshooting steps to test here:

Let me know if you’re able to run through the above, thank you!

34

Needs to wait a little as my sound systeM is in the living room where in the current uk heatwave the average temperature is over 30 degrees Celsius.

35

Understood @Wouter_Kolkman, we’ll be monitoring for your reply when you’re able to!

In the meantime, I hope you’re able to stay cool! :snowflake:

36

Hey, @Wouter_Kolkman.

Just checking in on this. We’re still monitoring for your reply, and I wanted to see whether you had a chance to revisit the steps we mentioned on your side. If you’ve got any updates for us, or if anything is still unclear, just let us know.

Please note, if we don’t hear back from you this thread may close automatically soon. If the thread auto-closes and you need further assistance, please submit a reopen support request via the technical support help form below and specify that the issue should be reopened. Thank you.