The crux of the matter when connecting different brands via HDMI I2S
is pinout matching since there is currently no standard. Assuming the output
is in fact I2S since they HDMI terminals visually look similar.
I'f I'm not mistaken the Pegasus has the ability to accommodate
several options to match the I2S pinout of other equipment.
Check with Musician or the web as I've seen a diagram posted.