notes
http://elinux.org/RPi_VerifiedPeripherals#USB_Sound_Cards
A post about installing USB sound cards
http://www.raspberrypi.org/phpBB3/viewtopic.php?t=20866
And another – with better detail
http://www.jackenhack.com/raspberry-pi-usb-audio-quality-problems/
http://raspberrypi.stackexchange.com/questions/3888/how-to-install-usb-sounds-adapter
Griffin imic with PD
http://iamthemightyjungulator.blogspot.com/2012/12/raspberry-pi-usb-sound-into-pure-data.html