[LAU] MotU Ultralite AVB observations.

[John Murphy]

On Sat, 7 Mar 2020 12:28:26 +0000 John Murphy wrote:

[...]
> I can only think that my dual booting and using it on Windows 10
> caused the trouble I was seeing when using it on Linux afterwards.

I seem to have narrowed it down to dependence on the setting of
'Clock Mode'. I do a lot of recordings from a 48kHz optical source
plugged into the S/Pdiff optical input. Seems to be that clock the
kernel can't use. Probably because it has somehow changed the device
to 44.1kHz (via 192kHz) and then demands a 44.1kHz clock.

If I set Clock Mode to internal, before booting Linux, or after
a failed start up, I see fewer 'clock source 1 is not valid'
messages in /var/log/syslog and jackd will work as usual. I've
even had sound in my (FireFox) browser, so Alsa must be working.

If I don't set Clock Mode to internal, /var/log/syslog gets the
full compliment of 6 blocks of 40 'not valid' messages, ending
with: [pulseaudio] module-udev-detect.c: Tried to configure
/devices/pci0000:00/0000:00:14.0/usb1/1-14/1-14:1.0/sound/card2
(alsa_card.usb-MOTU_UltraLite_AVB_0001f2fffe005ded-00) more often
than 5 times in 10s.

It had to be something like that.. Was doing my ed in a bit.

Big clue to the problem right there in the device's LCD display.
If the sample rate indicator keeps flashing - it isn't going to work.

-- 
John.