Recently I had to cover a bigger event including the need to grab pics from a tv live transmission directly into my camera. I managed to get the image via
BNC input from the broadcaster's SNG-unit, but when trying to get the sound as well using the XLR plugs - silence!! The workaround was to use the ordinary AV input and a couple of adapters. Actually some guys using a Sony Z1 next to me had the same problem.

Does anyone know, if there is an option of using the BNC input AND grabbing sound at the same time? And if so: Would the quality be significantly better compared with the 'mini-jack-option', as I suspect?

Maybe this was a possible line level or mic level issue? Or maybe your XLR inputs weren't active?

Bill

As far as I can tell, the XLR inputs are only active during camera mode.

I think you used the only mode to get audio in in VCR mode