Hi Claero,

With HDMI even where the is no video content from the source, there is still a video carrier signal that has the audio embedded within it.

In short "audio only" HDMI 1.4 outputs work just fine with the HD621, it will still be able to extract the audio content from the HDMI signal.

Regards,
Carl

861v6+ID40, HD621, 8000.2, 7200HC, 7200.2, SKYQ Silver, PS3, PDP-LX6090, QNAP TS870-Pro (8*6TB), Roon, iPadAir2.
[In Reserve] C15, MD600 (2*3TB), TwinStore RM (2*2TB)