Getting best audio from PC...thoughts please

Struggling to find much on this...but here goes!! :)

PC (MSI B360M /i5 8400 / GTX 1050ti) sends audio to AVR from Displayport, and Video by HDMI direct to TV.

Is there a better way of taking audio from the mobo (there's no s/pdif connection)??

Reason I'm looking at this is that, it seems the presence of the AVR (Anthem MRX710) seems to 'throttle' the video resolution to the TV...and this limits to 1080.

Hoped that by not taking audio from the graphics card, the screen might be 'freed up' to permit the higher resolutions it's capable of!!???

Hope that makes sense??
How about a PC soundcard with s/pdif o/p....or is that a daft way to go??