Sorry, to clarify I’m using an Apple TV 4K with HDMI to an LG G1 TV, then optical from TV to 861v4. I’m assuming there is some degradation in quality when the TV converts from HDMI to optical, maybe the signal even gets compressed to fit 5.1 into optical?

ATV4K -> LPCM over HDMI -> LG G1 (passthru) -> optical -> 861v4

Thanks,
Chris

#1: 861v4 | HD621| 218 | DSP8000SEUP | DSP7200.2HC | DSP5200 | SW1600
#2: AC200 | DSP3200 | DSW