Am 01.05.2015 um 00:00 schrieb Michael Biebl:
You could try blacklisting "snd-usb-audio" via $ echo "blacklist snd-usb-audio" > /etc/modprobe.d/no-usb-audio.conf Maybe that helps (you might need to rebuild your initramfs as well)
This did the trick. The sound is disabled, the boot is fast and the usb hub in the keyboard is still working. Perfect!.
Thank you all so much for your support. Matthias