Audio_alsa_sink problem on RPi2

Hello,

When trying to use audio sink in GRC I get following error:

audio: using audio_alsa
audio_alsa_sink[hw:0,0]: set_channels failed: Invalid argument

It’s the same with device “plughw:0,0”.
No error with hw:0,1 (HDMI output but i’m not connected to a TV)

Something related to speakers channels ? On the RPi, there is only one
jack output.

Thanks in advance for any help.