S/PDIF Digital Input/Output
S/PDIF input/output counts the coaxial or optical digital audio connections on an equalizer or DSP unit.
Coaxial S/PDIF commonly uses an RCA socket, while optical S/PDIF commonly uses TOSLINK. The connector count is distinct from the number of audio channels in the digital signal.
S/PDIF Digital Input/Output — Equalizer
These connections let a compatible digital source feed the equalizer and allow its processed signal to continue to another digital device. An input receives audio and an output sends it; a total I/O count does not show how many of each are available.
Compare direction and connector type as well as the total. An optical input cannot connect directly to a coaxial output with a passive cable alone. Check supported signal formats and sample rates separately, and distinguish coaxial digital RCA sockets from analogue RCA inputs or outputs.