E-Mu 404 Owner's Manual page 25

The optical digital TOSLINK input and output on the Digital Breakout Cable can be
used to transmit and receive stereo S/PDIF.
• PCI Card S/PDIF Input
• S/PDIF Output Format
E-MU Digital Audio System
Selects between coaxial or optical S/PDIF input. S/PDIF
out is always transmitted on both the coaxial and
optical outputs.
Selects between S/PDIF or AES/EBU format for S/PDIF .
This sets the S/PDIF-AES status bit, but does not affect
the signal level.
4 - The PatchMix DSP Mixer
The Session
17