Please read a description of the 6PMO/10K unit - it is 'Mono' type, which is confirmed by 3 outputs. That means you can use it to operate only one output channel instead of two. The other nice advantage of RK097 is a built-in rotary switch, so you don`t need to add a separate on/off switch to...

Quote:   TOSlink optical output is located inside a coaxial, just the way it was implemented in 1/8"/optical combo out.

st / stx actually has a coax/optical combo out and a mini-toslink <--> toslink adapter included.