Audio out mini-jack of Mac Mini to SPDIF DAC

Is there a cable to connect the audio line out mini-jack of the Mac Mini to an SPDIF coaxial input of a DAC?

If there is, will the sound quality be almost comparable to the standard "USB out --> USB in" or "USB out --> USB to SPDIF converter --> SPDIF in" configuration?

Any advice would be appreciated.
I don't know of any cable that will do the job but I have used a M-Audio CO2 bi-directional converter box which costs around $50. I am sure that there are a number of other boxes out there that can do the job.

Not sure about the sound quality aspects as this was just a temporary solution for me. Lots of debate around the sound quality of various options but for right now I am happy with my glass optical cable from my mini mac to Bryston BDA-1.
The mac mini has an optical spdif out built into the headphone jack requiring a special toslink cable that is readily available. I recommend real glass fiber ones.
YOu can get a toslink to coax converter like Dms1 mentioned, but I don't see how it could make a difference. In fact, the extra conversion could make things worse.

Get a good glass mini toslink to toslink cable and call it a day. Or, a usb to spdif converter will also work if you are set on coax. ]

With a good dac, the glass toslink can sound excellent. I have determined that I prefer the glass toslink out of a mac mini to a certain asynchronous usb/coax converter that I own. The toslink sounds more relaxed and musical in my system. However, the difference between the two is not night and day.
Thanks for the responses. Much appreciated.

Will the sonic difference between a glass toslink and plastic toslink cable be significant if used on an old (but decent) DAC of a Krell KPS-30i CDP?
Just like stemware for a good wine... Glass, not plastic, if you please...
Try lifatec...