Thanks Raffaele, You are right, once I'm loading manually the snd-usb-audio, all is fine. So, my work-around right now is running after each restart: $ sudo modprobe snd-hda-intel snd-usb-audio
I'm very pleased to have back sound at my computer, thanks to this mailing list!
As for .asound file, here is its content: pcm.pulse { type pulse } ctl.pulse { type pulse } pcm.!default { type pulse } ctl.!default { type pulse } -- With kind regards, Menashè