i have installed ubuntu, jack, ardour, hydrogen etc. as interface i use an m-audio fast track pro.
there are two cases:
i’m starting jack using qjackctl. in this case other programs can not connect to jack. they all say, they can’t find the server. however in contrast to the second case, i can use the input from my audio device (i.e. by connecting in and out in jack)
if i start ardour first and let it start jack, all programs can connect to jack but the input remains silent.
this way it is impossible to record anything.
Maybe you have a similar problem as I had on Debian Wheezy with non-english locale?
In my case it was/is a bug in qjackctl where the server name is (wrongly) translated and with this non-default name applications were not able to find the running server. You could simply try to enter “default” (without the quotes) in the “Name:” field of qjackctl’s config dialog.
