I have purchased a q75a having replaced my 55js8500. The new tv is connected to a denon 3200w same as the old one via arc hdmi
All settings on the new tv are in auto for dolby etc. I have the issue that sound drops out. Spoke to Samsung they put the tv on pass through. Have same issue. Samsung have put the tv on pcm now which has solved the issue. I'm try to indicate to Samsung why should I settle for PCM. I don't have thousand of pounds of hifi for pcm.
I know it's not an issue with the amp as I play my PC and virgin box through the amp without issue.