Problem connecting Rega Dac to Macbook 2008


I just bought a used Rega Brio-r and Rega Dac (not the -r version)
I´m trying to connect the Dac to my Macbook from 2008 but the device is not showing up on the Sound/midi settings. I run El Capitain OS.

I connected the Dac with miniToslink from Macbook 3.5mm output and Toslink into "optical in" on the Dac.

Should it automaticaly show up when I connect through the optical output or should I use "USB digital input" on the Dac and USB from Macbook? I wanted hi-def audio therefore I used the Toslink cable.

I´m not very good at this so I´m happy with all the help that you can give..
philsons
Ok but SHOULD the MacBook detect the Rega Dac through the toslink cable or is it only through USB connection? I had an Ifi microdac a few years back, connected with USB and I could find it in the settings
Every new OSX build is different. Can you check it with a friend's laptop using a previous build, Yosemite or Mavericks etc? That will tell you if El Capitan is the problem.