Specks says "2 pairs of ADAT optical I/O (doubles as S/PDIF) provide 16 in and 16 out " - so I think you lose S/PDIF when using both ADAT ports…
Specks says "2 pairs of ADAT optical I/O (doubles as S/PDIF) provide 16 in and 16 out " - so I think you lose S/PDIF when using both ADAT ports…