I was wrong in my thinking that jackd  had a stability problem. After spending (wasting) a lot of time troubleshooting jackd, a jackd crash finally occurred while I was siting in front of the machine, and I noticed that I lost the mouse and keyboard too for about 10 seconds. So this whole time, the trouble has been flaky USB hardware on the motherboard, not jackd.

Testing on a new computer has been flawless, for going on two weeks now.

That leads me to a question regarding Ubuntu Studio Control, which I have been using to manage jackd and additional audio interfaces via zita-a2j. I have Ubuntu Studio Control configured to use a Tascam US-4x4 as the main audio interface with 128 sample process frames at a 48 kHz sample rate on my test machine, with the built-in audio port on the motherboard as a a2j/j2a bridge. Audio to and from the motherboard interface is broken up with the zita-a2j and zita-j2a running as launched by Ubuntu Studio Control. Notably, the -p run option is set to 64. If I run zita-a2j myself with -p set nice and high, to 1024 for example, I get good clean audio, at the expense of latency on that interface. That's fine for me, since I still have good, low latency on the main interface. Does any one know where I can find the source code for Ubuntu Studio Control so I can investigate a fix to make this settable?

Thanks,

Ethan Funk