Is there any mini-jack converter for the Mac Mini

I have a Mac Mini also. . .

Assuming your DAC has an optical input, there's a mini-Toslink to Toslink adapater made by Audioquest and available from Music Direct for about $5. You would then use a standard Toslink cable. Or, you could go with a single cable that has mini-Toslink on one end and standard Toslink on the other. I ordered one from Lifatec (Lifatec.com).

I don't know if there's an adapter from the Mini mini-jack to an RCA style coax, but I'd be interested in finding out too.

I think optical is the only other digital output, Mono price has cables with the correct terminations.

I also forgot to mention that there are devices on the market that will convert the USB output from your Mini to an RCA type connection. Trends Audio and Bel Canto both make this type of converter.

The Blue Circle Thingee will take a USB input and output coax as well. Of course you can always go digital out (mini toslink) to toslink in on your DAC if you have that facility. I've used both and preferred the Toslink, but that's just me :-)