usb interface frustrations

[osnick]

Hi

So here is a conundrum which i have been bashing my head against and have finally run out of ideas

First the positive bit...

I have a behringer UMC204 USB interface and when in want to record using this into Audacity if i select ALSA in the software the interface appears in the drop downs for both record and playback and all is well, no sound quality issues, just works fine. So in terms of its main function all good so far.

Now the frustrating bit...

I would like to use the interface to record into Ardour and as the playback device in LMMS and it resolutely refuses to work with jack audio. In the jack connections it appears under the midi tab but not under audio or ALSA , i have gone into settings on qjack and can see the hardware is there in devices and can set it as as input and output, restart the jack server and still no joy, it is invisible under audio and ALSA. Both lmms and ardour work fine sending audio to system under jack but despite trying as many combinations of settings under jack as i can i cannot get the interface to appear.
if i set LMMS to use ALSA i get no sound at all

any thoughts? I am reluctant to throw away the interface and as it works fine in Audacity i am surenthere must be a software solution.

I am not a massive expert at the command line and am pretty new to linux audio at this level so may be missing the obvious :/

Running xubuntu 14.04 on a dell lattitude d630 with whatever standard intel sound lives on board (when finances allow a new machine is in the offing with a bit more capacity than this 6 year old lump!)

Thanks

Nick

[tatch]

when you set the interface in JACK you should be able to see "system" inputs/outs in the "audio" section (assuming you are using qjackctl) which refers to whatever interface is currently set

http://libremusicproduction.com/article ... arted-jack

[osnick]

Thanks for the reply:)

i can see the system inputs and outputs in the audio tab of qjackctl but when these are connected to lmms the software routes the input from the built in microphone on the computer. For whatever reason it ignores the connected interface. The interface appears in the settings for jack but seems to be ignored in terms of being used if that makes any sense!

[Pablo]

I suspect the problem is caused by some kind of confusion between qjackctl, jackd and jackdbus.

Take a look at (in a terminal window):

Code: Select all

cat ~/.config/jack/conf.xml

The first lines under the tag <driver name="alsa"> show the capture and playback devices.
Make sure they refer to the USB card, I suspect the contrary.

To start again, close all the jack-aware apps including qjackctl and do a:

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killall -9 jackd jackdbus

Launch qjackctl and try again