Question Is it possible to use the Impact Twin as a standalone  DA converter for 4 channels ADAT SMUX at 96 Khz  Answer This is possible. 
  • Set Impact Twin "stand alone Clock" to ADAT input / Sample Rate: 96 Khz
  • In TCNear Patchbay set output Line 1-2 and 3-4 respectively for ADAT 1-2 and ADAT 3-4 
  • Disconnected Impact Twin from computer.
  • Feed the ADAT optical input with 4 channels at 96Khz. They will come out as analog signals in analog outputs 1 to 4.