leotis
I am told by someone who should know that the digital volume control on the Oppo produces a signal that is not lossless.
Correct it’s not lossless, If you had to used that digital domain volume control below 75% of full up because it was too loud, you may very well have started to "bit strip" the resolution, from 16bit down to 14bit to 12bit to 10bit ect the lower below 75% you went. The only way out of that one is to have a passive in between and leave the Oppo digital VC up full.
Cheers George