[LAU] Motu M64 Madi interface (not) class compliant?

[Peter P.]

* Paul Davis <paul at linuxaudiosystems.com> [2021-04-18 03:43]:
> On Sat, Apr 17, 2021 at 4:22 PM Peter P. <peterparker at fastmail.com> wrote:
> 
> > * Peter P. <peterparker at fastmail.com> [2021-03-12 18:43]:
> > > Hi list,
> > >
> > > can report that the Motu M64 Madi interface does work with a limited
> > > channel count of 24 for input and another 24 for output (instead of 64
> > > each). So if you are coming across a venue or employer that already has
> > > one, you are good to go. Sample rate needs to be set on the device
> > > before starting jack. Of course, buying the card for oneself for so much
> > > money getting only one third of the channels seems useless linux users
> > > IMHO.
> >
> > I can add now that the card does not work reliably in class compliant
> > mode with external sync clocks. It will randomly switch back and forth
> > output channels in banks of eight, cause clicks and distortion and
> > aliasing artifacts.
> 
> 
> The bank switching is a known problem with other MOTU USB devices, and has
> been "solved" by using specific firmware releases (e.g. for the MOTU
> Ultralite AVB) which may not be available anymore or for your specific
> device.
Thanks Paul, that is good to know! Does anyone have more info on this
back switching and associated firmware updates?
 
> I do not believe that the aliasing is caused by bank switching, but by
> (possibly) an ALSA driver bug. It generally goes away within a few minutes
> or on device restart.
But wouldn't that driver bug affect all class compliant interfaces then?

cheers, P