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..
128x128philsons
Your Macbook might not have Toslink out (Macbook Air 2008 doesn't).  You can verify by checking "About this Mac" and then "Audio".  If it doesn't show S/Pdif there then you don't have it.   You could use USB but it will be limited to 16-bit and 48kHz by your DAC.  It might also be synchronous USB, meaning that the clock for D/A converter is synchronized with computer (asynchronous has independent clock).  You can also get asyc USB to S/Pdif converter.
https://apple.stackexchange.com/questions/46605/how-do-i-tell-if-my-mac-supports-mini-toslink

Yes it supports optical out, the combined 3.5 mm jack. I can see the red light as well, but why can't I get 192khz in the sound/midi settings, the highest option is 96khz, 24bit 2-channel stereo and I don't find the Rega Dac as an option..

Does the toslink only work oneway, and USB should detect the Dac in the list?
My Mac Mini S/Pdif is IN/OUT.  Below copied from "About This Mac":


S/PDIF Optical Digital Audio Output:

Connection: Combination Output

S/PDIF Optical Digital Audio Input: 

Connection: Combination Input