Jack... - Linux-audio-user

19 Dec 2016

I have 3 different PC's (one desktop, two laptops) running Ubuntustudio
16.04.

On the desktop I rarely do any capture. It uses jack/ffado/zita-lrx to
output to a AF12 as a tri-amped playback system. No issues, just works.

On the older laptop (Dell XPS1530) I routinely switch between the on-board
sound and up to 32in/8out from/to an X32 via USB. Sometimes setup to input
from the X32 and output to onboard sound. All configs with jack, again, no
issues, just works.

On my newer laptop (System76 coreI7) I can use the onboard sound with, for
example, Clementine set to output to alsa or pulse and it works fine. If I
attempt to use Ardour at the same time with it's own alsa the combined
output (if Ardour and Clem are playing) audio is distorted. Separately fine.
If I attempt to use jack, for example use qjackctl to start jack. Qjack
just hangs. To stop it I jhave to use kill -9. If I then start qjack, it
shows the I/O connections (pulse source/sink and capture/send). But if I
send audio to it from Ardour (to jack) or Clementine (jack or pulse) the
audio sounds like it's in slow motion. If I plug in the usb from the X32,
start qjackctl, set the I/O device to the X32 usb, viola, works just fine
for only the I/O ports exposed by the X32 USB. Any attempt to use mixed I/O
(as described for the Dell above) results in qjack and jackdbus hung and
only kill -9 will stop them.

I don't HAVE to have this work, but it is nice to be able to plug
headphones into the PC to monitor whats coming into Ardour from the
X32...but, I'm wondering if I'm missing something simple, or this is just
the way this particular combo of hardware is going to work.

Trouble shooting suggestions? Or, just leave it as an unsolved mystery? ;)

Regards,
Mac