Installed ffado drivers and now jack won't start; no drivers (including alsa) recognized.
I installed the ffado drivers in an attempt to get my Presonus Firebox working. After that jack refused to start at all, insisting that no drivers were in existence. I did a little more research and then elected to unsinstall Jack (I was running .118) and install 1.9.6. Same result. Jack won't start with any drivers selected at all; they're all "unknown" including Alsa. Now, I know Alsa is working... my other apps have sound. Here's some of the message window output from qjackctl:
21:05:32.183 JACK is starting...
21:05:32.183 /usr/local/bin/jackd --no-realtime -r -dalsa -dhw:0 -r48000 -p1024 -n3
21:05:32.185 JACK was started with PID=30359.
Unknown driver "alsa"
Copyright 2001-2005 Paul Davis and others.
Copyright 2004-2010 Grame.
jackdmp comes with ABSOLUTELY NO WARRANTY
This is free software, and you are welcome to redistribute it
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21:05:32.191 JACK was stopped with exit status=255.