There is no audio out when a VC880 is connected to a VM5808H.

There are two EDID settings in the VM5808H - ATEN Default, and Port 1.

- If the VM5808H EDID mode is set to port 1，the VC880 must be connected to a HDMI monitor. If there is no monitor on port 1 there is no source for EDID information thus no audio

- If the VM5808H EDID mode is set to ATEN Default, the audio works properly because EDID information is supplied internally by the VM5808H