How set USB soundcard as recording device

New sound devices should appear in the list automatically. You can also press the small refresh-button to refresh the Source - list.

To debug your system:
Also goto the "Addition settings" dialog and select "Recording commands" tab.
There you can modify and test various recording pipelines. Press the "Show Cmd" button. It will tell you how to list all available audio (source / input) devices in your system.

 I do also print the commands here. Run one of these commands in a terminal window.
$ pactl list | grep -A3 'Source #'
$ pactl list short sources | cut -f2

You may need to install the pactl (or pulseaudio-utils) package first.

Then tell me if you can see your USB sound card in the list. Ok?

I do not have pulse audio installed. I tried to install pactl-utils, but it will pull in pulse audio, which I do not want to do on this system (Opensuse Leap 42.1/XFCE).

I tried to use the above commands on a Debian system but got errors.
$ pactl list | grep -A3 'Source #'
bash: pactl: command not found

$ pactl list short sources | cut -f2
bash: pactl: command not found

Pulse Audio is not listed as a dependency. Can I not use audio-recorder with alsa?

Thanks..

No you can't.

If you study the recording pipelines in the "Additional settings", "Recording commands", [Show Cmd], you will notice that the commands use "pulsesrc". Like this:

gst-launch-1.0 -e pulsesrc device=alsa_output.pci-0000_00_1b.0.analog-stereo.monitor \
! queue \
! audioresample ! audioconvert \
! audio/x-raw,rate=44100,channels=2 ! lamemp3enc name=enc target=0 quality=2 ! xingmux ! id3mux \
! filesink location=test.mp3

But it should be rather easy to patch the program so it also uses "alsasrc" and alsa devices (like hw:0).

List alsa devices:
$ aplay --list-devices

Please tell me if you find good recording pipelines that uses alsasrc.
Google for: gst-launch alsasrc -ev device=
Rest of the pipeline is same for pulsesrc and alsasrc.

List all attributes on alsasrc:
$ gst-inspect-1.0 alsasrc