[Ardour-Dev] Alsa works, Ardour/Jack fails

[Mike Mazarick]

 Patrick Shirkey wrote:
> This may be related to volume levels? Have you tried adjusting the
> output of ardour or the alsamixer settings?

Yes.   However,  I should mention that as a rule I'm testing this out by
selecting the output on the 'Ardour Mixer' strip.  This works for the first
24 channels, but I get the 'bad guitar cord' effect on the last 4 channels. 
> 
> Also, have you tried using another jack app to playback audio to each
> channel like alsaplayer for example?

Aplay seems to work fine.  Of course, I don't have an 'ardour equivalent' so
that I can determine if it is the driver or alsa/jack.
Since the driver I'm using isn't in the alsa tree, all the 'normal stuff'
has to be done by hand and I'm unsure if the RealTime is effective.   Using
'setpci' and giving the audio devices higher priority doesn't seem to have
an impact.

I am not completely familiar with the universe of Linux audio.   If there is
another app which uses Jack to test this situation, it would greatly
simplify things and help me figure out the driver vs jack vs ardour issue.
Since Jack/Ardour works with RME and other cards, I'm thinking driver, but
it would help if it was confirmed that it also worked with other sync'd
cards like several Delta 1010s in a system.

> What you are doing with 4 synced sound cards is fairly unusual and if
> you are using alsa dmix to run them as one card there could well be
> some outstanding bugs in the driver You could also try running them in
sync
> with netjack.

That's what I get for trying to 'kill two birds with one stone', providing
QC on a driver by 'stress testing' it's limits and working up a new
application.
   
It becomes necessary to carefully craft the stone.

> Are you using the plughw interface?

In order to simplify this situation (and because I'm mainly interested in
'pro level' stuff rather than consumer), I make it a point to remove all
pulseaudio stuff.   It may be useful at some point in the future for me
(later), but there are configuration error messages that show up in the
/var/log/messages file that are distracting.