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

Wouter_Kolkman · April 2, 2026, 4:37pm

Hi! What’s not quite right with Roon?

· None of the above quite fits

None of the above quite fits

· None of these quite match

Tell us what's going on

· MacOS 26.4 - fails to play after change of sample rate

Tell us about your home network

· Problem also happens with playback from local SSD (using MacMini M1 as server, 2nd as Roon Bridge connected via CAT 8 direct. Server connected via WiFi to router 1m away with fibre connection)

Wouter_Kolkman · April 2, 2026, 4:57pm

Hi! What’s not quite right with Roon?

· None of the above quite fits

None of the above quite fits

· None of these quite match

Tell us what's going on

· MacOS 26.4 - fails to play after change of sample rate

Tell us about your home network

· Problem also happens with playback from local SSD (using MacMini M1 as server, 2nd as Roon Bridge connected via CAT 8 direct. Server connected via WiFi to router 1m away with fibre connection)

Wouter_Kolkman · April 2, 2026, 4:59pm

Additional information: DAC connected via USB; when sample rate changes there is no output available on other output devices such as Roon Server itself. Playback as normal after reboot or when changing Audio settings for the DAC e.g. Integer mode toggled and saved.

alex_h · April 3, 2026, 5:49pm

Hello @Wouter_Kolkman ,

Thanks for reaching out to our support.

Can you please share with us the screenshot of the settings of this DAC in Roon ?

Also, please try to set the resync delay to a higher value, it might help in resolving the issue.

Thanks.

Wouter_Kolkman · April 4, 2026, 11:29am

Screenshots attached.

Same DAC used with Roon for over 4 years.

benjamin · April 8, 2026, 6:34pm

Hey @Wouter_Kolkman,

Thanks for the update and screenshots! This behavior, where a sample rate change hangs the audio output across the entire system, usually points to a CoreAudio lock-up or a synchronization “handshake” failure between the Mac and the DAC’s USB interface.

Since toggling Integer Mode or saving a setting “wakes” the device, you are essentially forcing Roon to re-initialize the driver handshake.

In your screenshots, I noticed Exclusive Mode was toggled No in one view and Yes in another.

Ensure Exclusive Mode is strictly set to Yes.

Without Exclusive Mode, macOS tries to mix Roon’s audio with system sounds. When the sample rate changes, the macOS mixer and Roon may fight for control, leading to the "silence" you're experiencing.

I’d also see if trying to reduce Resync Delay to 500ms or 0ms to see if a faster transition prevents the driver from timing out. Conversely, if the Denafrips is “clicking” but not playing, keep it high.

The screenshot also shows the Max Sample Rate at 768kHz. While the Denafrips can handle this, the USB handshake at these extreme limits can be fragile on macOS.

Temporarily set Max Sample Rate (PCM) to 192kHz and Max Sample Rate (DSD) to DSD128.
Then, play a playlist that alternates between 44.1kHz and 192kHz. If it no longer hangs, the issue is likely the USB cable bandwidth or the Mac's handling of the highest-tier sample rates.

I would also test a hard-wired connection from your Server to your router via Ethernet.

We’ll be monitoring for your reply and results, thank you!

Wouter_Kolkman · April 8, 2026, 7:33pm

Thanks for suggestions and explanations:-)

Wouter_Kolkman · April 8, 2026, 7:40pm

Reducing max sample rate and sync to 0 looks positive as first impression.

benjamin · April 13, 2026, 8:51pm

Thanks for letting us know @Wouter_Kolkman - how did things perform over the weekend?

Wouter_Kolkman · April 13, 2026, 9:26pm

Problem still persists - reduced max sample and reduced sync delay. Used solely exclusive mode.

noris · May 11, 2026, 9:18pm

Hello @Wouter_Kolkman ,

This thread has been reopened at your request. Can you please reproduce the issue and let us know the exact local time + date + track you observe this next? We’ll enable diagnostics to see if there are further clues in the logging.

Wouter_Kolkman · May 12, 2026, 5:57am

Hi Nori’s, thank you for reaching out promptly. I upgraded my Roon server and Roon Bridge to macOS 26.5, and now changing track with different sample rates are fine - I tried 4 tracks so far. I did report the problem to Apple, but you never know what changes between releases - fingers crossed.

vadim · May 15, 2026, 1:55pm

Hello @Wouter_Kolkman

Thank you for the update. Please let us know in case of any issues.

Wouter_Kolkman · May 16, 2026, 4:57pm

Single ‘hiccup’ today Saturday May 16th 17.55 British Summer Time. I had to restart the track a few times. The 2 tracks played were from local SSD - wired from Roon Server to Roon Bridge Gbit.

noris · May 20, 2026, 9:54pm

Hey @Wouter_Kolkman,

Based on the recent diagnostics, it looks like the hiccup was not limited to playback itself. The localhost and your Mac mini disconnected around the same time, as well as the Denafrips and Mac Mini RAATServer, which points to a broader network interruption.

That lines up with the brief interruption you saw on Saturday at 17:55, even though the tracks were playing from your local SSD over a wired connection to Roon Bridge.

Do your router logs show a network disconnect around the time? Is it possible to connect your Server via Ethernet directly to the router if you haven’t tried this yet?

noris · May 27, 2026, 8:28pm

Hey @Wouter_Kolkman,

Just checking in on this. Were you able to take a look at your router logs for a disconnect around that Saturday 17:55 interruption, and have you had a chance to try connecting your Server directly to the router over Ethernet? If you’ve seen any new clues since then, send them over and we’ll take another look, thanks.

Wouter_Kolkman · May 30, 2026, 1:36pm

Thanks for checking - I just changed provider, so had to return the router. However had a similar occurrence once more today at 2.27 pm British SummerTime, from local storage playback. From server to Roon Bridge via Gbit Ethernet.

benjamin · June 4, 2026, 12:49am

Hi @Wouter_Kolkman,

Thanks for the update! We were able to review a fresh Roon Server diagnostic report and saw the core pattern here. Bridge RaatServer dropping briefly, then recovering, followed by a long RTT/clock-resync storm, is the same mechanism @noris identified after the May 16 event. It’s not a sample rate issue (the May 26.5 fix resolved that). It’s the Bridge’s RAAT connection momentarily collapsing.

With that, the direct Ethernet link (192.168.100.x) between the two Mac minis experiences periodic brief stalls. These manifest as either:

A TCP keepalive timeout (no data received for >10000ms) causing a reconnect
A port going Connection refused (the RAATServer process on the Bridge restarted)

When the Bridge RAATServer restarts or the direct link stalls, this is what cascades:

The Server's RAAT control connection to the Bridge drops
RAAT clock sync loses its reference, drift and RTT spike wildly (as seen in the massive 5014 ppm / 237ms RTT burst on May 30 12:18–12:23)
Playback continues on buffered data for a moment, but if the disruption lasts long enough or the buffer empties, audio stops
The Bridge rediscovers itself and reconnects, usually within seconds to a few minutes

The direct cable link is the common thread. Every drop event in these logs involves 192.168.100.101 going unresponsive, never 192.168.1.118. The router-subnet path appears stable; it's the direct cable that's intermittently failing.

The most actionable test: Disconnect the direct Ethernet cable between the two Mac minis entirely. Run Server and Bridge connected only through the router via Gbit Ethernet. The 192.168.100.x subnet should disappear, Roon will use 192.168.1.x for everything, and if the dropouts stop, the direct cable (or its network configuration) is definitely confirmed as the cause. If they continue, it rules out the cable.

Thank you @Wouter_Kolkman