Can I connect a S/PDIF Optical signal to Quartet's Digital Inputs? Chris April 19, 2021 19:47 Updated Quartet's Optical Inputs only work with ADAT or SMUX devices. They do not accept S/PDIF Optical signals. Related articles How do I play computer audio through Mini-Me SPDIF or AES digital outputs? Comments 0 comments Article is closed for comments.