1 (edited by fables Yesterday 20:25:16)

Topic: Audio dropouts with UFX iii on MacOS 14.7.1 (23H222)

Now  that I have switched to a brand new UFXiii (from Red 16line), trouble shooting mode has started again.

I am running on a MacBook Pro M1. MacOS 14.7.1 (23H222)

Audio dropouts last between .3 and .7 seconds so far, when measured. To measure, I use a test tone generator in Ableton Live and record on the interface directly to DURec. The dropouts therefore a not caused by the speakers or the connection to them.

See attached screenshot of what a sine wave looks like, recorded directly with DUREC. As you can see, something is off and then the interface seems to shut down audio.

Firmware 2.0

Driver 4.16

I have removed any stray kernel extensions as discussed in other threads. I do not get any error message whatsoever and have no idea where to look for the issue.

Any help appreciated

https://i.imgur.com/gQvgaZL.png
https://i.imgur.com/unDBuBJ.png

2

Re: Audio dropouts with UFX iii on MacOS 14.7.1 (23H222)

Is that yellow region the dropout you're referring to? What about the weird discontinuities in the test signal?

Re: Audio dropouts with UFX iii on MacOS 14.7.1 (23H222)

Please try a different USB cable and/or USB-C port. Directly to the Macbook with no hubs.
Also test USB 2.0 mode. See manual and look for "interface mode".

Regards,
Audio AG Support

4

Re: Audio dropouts with UFX iii on MacOS 14.7.1 (23H222)

Steffen wrote:

Is that yellow region the dropout you're referring to? What about the weird discontinuities in the test signal?

Hm yes. As you can see, the sine wave suddenly isn't a sine wave anymore, then the audio stops. The yellow region is only there to measure the length of the dropout. Focus on the sine.

5 (edited by fables Today 10:24:52)

Re: Audio dropouts with UFX iii on MacOS 14.7.1 (23H222)

Audio AG Support wrote:

Please try a different USB cable and/or USB-C port. Directly to the Macbook with no hubs.
Also test USB 2.0 mode. See manual and look for "interface mode".

No hubs, directly connected, everything else disconnected. Tried two of the ports, no difference. I am not using USB 2 as I need the Madi channels, that is why I bought the interface in the first place.

I also won't use class compliant mode, as I need TM, which is the other reason why I bought the interface.

Reading for hours through the various posts on this forum I have collected the following info, although nothing is "official"

- M1 USB audio has a problem, Thunderbolt doesn't
- the v3.3 Kernel driver might help, as one can set a higher buffer value, but Apple is discontinuing direct access to the Kernel, which is why RME has driver v4.7
- USB2 has no problems, because less channels mean less data. That is also why other RME interfaces have no problem, like the BabyFace.
- class compliant mode might solve it (not sure why it should, maybe higher buffer settings?) but then TotalMix is not available anymore except through an iPad - more clutter & devices, not less, I don't like it.
- it seems to be an Apple problem that also other interface providers struggle with, but nobody has heard anything from Apple regarding a fix.

--------

Meanwhile I did a couple more tests. I tried to open a lot of memory-hungry applications and sometimes, audio will stop for several seconds if I do so. ActivityMoniror did not show any memory swapping.

Also, when I play audio, sometimes it doesn't simply stop but does have some distortion before it stops. Looking at what happens to the sine wave test signal, it is very well possible that I hear some distortion in an audio signal before it is shut off.

Obviously, RME won't be able to help much or else this wouldn't be an issue anymore.

It seems to me that issue is not solvable from our end at this time. I will consider the UFX+ instead, which has Thunderbolt.