Hello
In the early days of CD playback there was a difference in player to player performance, however, the difference was usually very subtle and at very low signal levels, a shortcoming called low level non- linearity. As players moved from multi bit ladder type D/A converters to one bit converters, this issue started to become a non issue even with low cost players.
You are correct with statement that one digital signal vs. another digital signal of the same source should be identical, which is the case unless there was a design flaw, or player malfunction, of one or both players being compared.
As far as using the digital output from the DVD player to play CD’s, it’s possible and more than likely that it’s not the receivers converter that’s degrading the sound, but some other function of either the DVD player or your receiver, or both.
Your final question is very hard to answer as it pertains to the way music should sound, which is always a subjective topic, but basically I suggest encoding mp3’s as high as possible as any good sound system will reveal flaws in mp3’s encoded at lower bit rates, particularly with symphony type music. There are many more variables to consider as well.
Good luck and welcome to the forume!
