I think you are getting stuck in the virtual world. The query is whether it will sound better relying on a source's digital volume control for attenuation or the analog volume control on an amp.
Let's assume you want to listen at 25% volume, a common level. The digital source, to attenuate by 75%, necessarily throws out a lot of bit-depth resolution - regardless of internal upsampling or bit-depth changes (neither of which create more or "better" data). There is then the potential issue of feeding the amp an overly low level input and pushing the gain structure of the amp.
Leaving the digital volume control at 100%, feeding a full range signal to the amp, and using the analog volume control will result in better sound.
Of course if you prefer the sound of a heavily attenuated digital volume control feeding a low level signal to an amp you should listen to this. Most will prefer the sound of cleanest source/analog attenuation.