Coaxial to mini-optical cable/converter that doesn't need a

I'm about to buy some digital coaxial cables to run my MPC1000 into and out of my audio interface, but macbook pros can take and send digital audio via mini-optical into the audio jack. It's aways good to have more routing options, but the only converters I've found seem to need power, and I'm not interested in using 3 outlets just to get more options.

Wondering if anyone found something.

Thanks!