Can I use the HDMI Out on my macbook pro retina for audio without connecting a video device?

While the MBP has TOSLINK output from the headphone jack, TOSLINK does not have the bandwidth to carry the high resolution audio from many blu-rays and DVD-Audio disks. I would like to hook my MBP to an audio-only HDMI sink so I can pipe the multichannel output to my surround speaker setup.

My concern is that the MBP will get "confused" and do one of the following things - both of which are "bad":

1) It will decide that a video device is there, and put the desktop on the nonexistent HDMI display OR

2) It will decide to send no signal at all (no video, no audio) because it sees no video device.

Any thoughts on this?

In short - thinking of using something like this: http://www.ambery.com/2hddodtsdihd.html

with the HDMI out of the MBP and then piping its 6 discrete analog outputs to my old (but excellent for computer speakers) Logitech Z680 setup.

But I want any movie video to remain unperterbed on my Thunderbolt display. And if I am not watching a movie and am just listening to multichannel FLACs or something, then I'd like to run the media player normally and have the usual desktop on my MBP or Thunderbolt display.

Any thoughts?

Thanks to all!!

-L