how can route to spdif as main output?

in windows 7, spdif(opt) can be activate! it’s easy… just go to ‘setup’ in MR editor, and choose the optical spdif output in main output section. That’s be done.

But be not in OSX Mountain Lion (10.8.5 )

default activating output is only analog output, and it cannot be changed. (how can i change to another output as main output?)

When i go to ‘setup’ in MR editor, that show just condition.
(Word clock master, sample rates, clock source, etc…)

There is no exist the main output section in MR editor.
How can I route to spdif as main output for macbook’s sounds?
Level meter is mooving in analog output 1-2. not spdif output.
I can’t get the sounds.

i wanna use spdif optical. it couldn’t be activated… main output is not changed in OSX…
how can i change to spdif?
I think that is need update… may be.

I’m in TOOLS ver 1.7.6 with Mac OSX 10.8.5

Please Help me.

Thank you.