MAC istructions at HRT site seems to be incomplete so there is something to do after installation.
Open Audio Midi settings, set to following
http://www.broby.dy.fi/audiostreamer/Picture3.png
If sample rate is set 44100 audiostreamer freezes sometimes (no audio output,unplugging and plugging back unlocks) and if samplerate is set 96000 it interferes with other USB devices so that a fast mouse move (logitech wireless USB mouse and keyboard) generates loud hissing noise.
I guess 96000 or 88200 samplerate could be used with original MAC keyboard and mouse.