Can the Duet 3 use an ADAT Extension? Sam August 19, 2021 01:05 Updated No. The Duet 3 does not feature any Optical I/O, therefore extension via ADAT is not possible. For more info on the Duet 3, check out these great resources: Duet 3 User's Guide Duet 3 Knowledge Base Related articles Is Duet 3 compatible with iPad OS and iOS devices? How does Duet 3 compare to other Apogee units? Updating Apogee Duet 3 Firmware Is Duet 3 Compatible with my Apple Silicon M1 Mac? How to connect Duet 3 to iPhone (or iPad with Lightning port) Comments 0 comments Article is closed for comments.