Audio Quality on Digital Out on Mac Mini

Curious to find out what type of audio quality I can expect if I use a Mac Mini's digital out to a B&K Ref 50 Pre-Amp. I'm assuming that this would be no different that feeding a digital signal from a CD or DVD player, correct. Any thoughts would be appreciated.

Also, the Mac Mini only has a mini connection. Does the adaptor to converter the mini plug to toslink degrade the signal significantly.

Thanks for the input.
I use the digital out of my iMac to a Benchmark DAC1 and I am quite happy. I didn't want to use an adapter and didn't have to, Monster makes a cable that has mini-optical in one and and regular optical in the other (I think I paid about 45 dollars online).

USB is probably better, but I didn't want to replace my DAC for that.
there are other threads that discuss this. i also use a mini as a music server with airport express units in different parts of the house. i use the toslink cable to a jitter reducer/remover device then to an external dac then to my integrated amp. there is a huge improvement using an external dac, and there was a huge improvement inserting the jitter device before the dac. i use this method in all my non-dedicated listening room setups (den, rec room, outside speakers, and bedroom). i am in the process of getting the right equipment to evaluate a jitter device (still haven't purchased this) to use before a new Manley dac in my dedicated listening room that could replace my classe cd player.
Mozartrules: Can you give more detail about the Monster cable you got? I am looking for one that can connect to my MacBook Pro audio/digital output and the other end to my DAC1's optical input. Thanks
look for the ipod mini jack to optical cable. you can buy a complete monster kit with a few cables or just get the mini/optical cable at your local mac store