The Delta1010AI is an adat interface for use with the Delta1010. It does not add an additional 8 inputs and outputs to add up to 18 IO, but rather it replaces the analog IO depending on the switches. Basically, inputs 1-8 can either be from Adat or Analog. Outputs 1-8 can be to Adat, Analog, or both at the same time. S/PDIF 9-10 is unaffected.