Use of optical out on new macmini dual core

There is no option, the mini will automatically detect an optical cable, you will need to set the bose to play from an optical input.

Everything is automatic.

In DVD player...sometimes it needs to be setup correctly. Go into preferences >> disc setup >> audio >> digital out

With the exception, as noted of the DVD player, it's System Preferences>Sound>Output. Make sure you used the mini-toslink/optical adapter and that the cable is securely snapped into an INPUT port on your bose system. Everything will be (as noted) auto-detected, and you should see the option:

Digital Out Built - In Output

Select it. If you have multiple adapters for sound (ex a usb audio adapter), then you might want to select the digital output for use only w/ dvd player. Choose where you want your system sound and alerts sent in the other tabs of Sound.

On your bose unit you may have both analog and digital inputs for the same source. I'm not questioning your competence, more my knowledge the equipment you are utilizing. Make sure you select OPTICAL as the input for that source.

For example,

You have buttons for Video 1, Video 2, and DVD. On the back you have a coax digital, a couple of toslink/optical digital connectors and a bunch of RCAs. If you hook up ALL the wires from each device then press Video 1; it MAY just use the analog connections...and since you're ONLY sending digital you won't hear a thing.

If you have 'auto-detect' for analog or digital it probably prioritizes digital over analog and will merely work IF SELECTED. Some systems may do the reverse.

Good Luck,
-j