• Registered: 2025-03-21
  • Posts: 21

Topic: AVB Stack constantly breaking on mac os

Hello,

I am running an AVB network (12mic, USB digiface AVB, AVB Tool). The digiface is connected to a mac mini m4+ Tahoe 26.3.
Drivers and hardware update are latest versions.

Nethertheless, quite frequently, after some minutes the AVB stack seems to break down. It looks to me, that a different sample rate come into play (for no reason?).

Is that a known problem? Is there a fix?

Best regards
Claus

PS: It never happend when there was simply a direct connect between the 12mic and the mac with the digiface AVB. It only started to occur after installing a network. Silly enough, there is another mac (an older M2, also running Tahoe 26.3) which also connects to the AVB network via a digiface AVB. There are no issues on that side).

2 Reply by MC

  • MC
  • MC
  • Administrator
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  • From: Germany/Thailand
  • Registered: 2007-04-06
  • Posts: 26,996

Re: AVB Stack constantly breaking on mac os

Same firmware in both DF AVB? Same RME AVB Controller version used?

Regards
Matthias Carstens
RME

MC's Website

  • Registered: 2025-03-21
  • Posts: 21

Re: AVB Stack constantly breaking on mac os

Yes, indeed. All identical. But the DF AVB at the M2 serves as masterclock. (using CRF)

  • Registered: 2025-03-21
  • Posts: 21

Re: AVB Stack constantly breaking on mac os

No idea?

  • Marc S
  • RME Developer
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  • Registered: 2019-06-11
  • Posts: 155

Re: AVB Stack constantly breaking on mac os

Hi!

Can you try to swap the clocking, making the m4+ Digiface clock master? Does the problem shift to the m2 one now?
If not: Try to swap the Digifaces, so we can exclude a hardware defect as root cause.
If yes: Try to make the 12mic clock master. Does that help?

Best regards
Marc

  • Max
  • Max
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  • Registered: 2007-05-09
  • Posts: 358

Re: AVB Stack constantly breaking on mac os

In addition to what Marc said:

- Are you using your MOTU Switch? Or Netgear? Or both?

- What do you mean by "break down"? Are you observing something like a reload in the Digiface AVB Controller?
related: What makes you think that a different Sample Rate comes into play?

  • Registered: 2025-03-21
  • Posts: 21

Re: AVB Stack constantly breaking on mac os

Thanks. Yes - I do use netgear M4250 switch. Breakdown means, that the sampling rate for the digiface (M4) changes (for no obvious reason) from 96 kHz to 32 kHz. Changing to 12mic as master is quite unconvenient. I use the M2 because this computer is "always on" - meaning there is always a master clock to the avb network.

Many thanks and best regards
Claus

  • Max
  • Max
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  • Registered: 2007-05-09
  • Posts: 358

Re: AVB Stack constantly breaking on mac os

So the Digiface AVB is connected to the M4 Mac, synced to internal 96 kHz, and other devices are listening to its CRF stream. You have a M4250 with current firmware (?), and we are searching for the cause for a frequent change of sampling rate that you observe in the Settings dialog (or in the AVB Controller?) about five minutes after connections are established.
Could you take a short video of that situation, showing the RME AVB Controller and the Digiface Settings dialog?

Also, did you by any chance activate AVB/EAV-mode (or Virtual Entity) on the Mac's internal network adapter and connected this port also to the Netgear Switch?