I have a Focusrite Saffire that has lots of nice, quiet preamps and ADC channels. I managed to get an old Mac to connect over FireWire and using the Focusrite Control app, I configured the routing to map all the analog inputs to ADAT. That works great but it's always at the wrong sample rate, and I can't change that without getting the old Mac out. Maybe I'll look into one of these rPi shields too. Anyone got any reverse engineering tips for the control protocol?!