Hi elgrecomac,
you can use a cale like this (XtremeMac XtremeHD Toslink Audio Cable) from the apple store.
Optical out from AppleTv to optical input into MHT200 McIntosh (one of the three digital input available).
Otherwise you have to split "HDMi" in 2 signals (1) video to your TV/Monitor and (2) audio to your MHT200, more expensive the first one and probably worthless for the kind of use.
Hi elgrecomac,
you can use a cale like this (XtremeMac XtremeHD Toslink Audio Cable) from the apple store.
Optical out from AppleTv to optical input into MHT200 McIntosh (one of the three digital input available).
Otherwise you have to split "HDMi" in 2 signals (1) video to your TV/Monitor and (2) audio to your MHT200, more expensive the first one and probably worthless for the kind of use.