Resolution drop

You are referring to digital volume control. If the volume is controlled in the digital domain, it is controlled by stripping bits, so effectively you are reducing the resolution. The further you get from 100% volume, the more bits are stripped to create the reduced volume. So, 100% volume contains bit perfect signal. Anything less than 100% volume loses some bits and the future you get away from 100%, the more bits and resolution are lost.

This is my rudimentary understanding of the potential issue.

Are you connecting the analog outputs from your Oppo directly to a power amp? No pre-amp for volume control? And are you using the digital volume control built-into the Oppo to control the volume? 

+1 @reubent , digital volume controls will sacrifice resolution to control volume. An analogue pre-amp solves this issue and will bring a wider, more dynamic sound too, however good pre-amps will reveal shortcomings of the source components too if not properly matched.

@reubent Your explanation makes great sense, worded well and I won’t forget it anytime soon, thanks. The words bit stripping did come to mind, I thought that will be another question. I see now I was wrong. What I remember of the plan was, using an integrated amp in a home theater set up.

Turns out, the Oppo105 is not a bit stripper and it was suggested to look for a high end pre/pro instead, by the dealer.

The details left me, but, I did invest in a HT bypass preamp.

I was concerned with the whole lowering resolution part and now I have more search words to investigate this further. Any websites that you can point to? Earlier today, bit stripping didn’t have many results.

Again, thanks for the explanation.

@2020matters  - A quick Google Search of "Digital Volume Control" will find links to some articles that discuss the potential loss of resolution with digital volume control.

If I recall correctly, the issue has been reduced/mitigated by increasing the digital word link from 16 bit to 24/32 bits or more. The original problem was from a time 20+ years ago when digital audio was in its early development period.