Jim, your example doesn't account for the conversion method, analog buffer, etc. But given the same dac and output electronics, lets say using a CD player with digital input jack to access the DAC portion, you might expect that the ripped file to sound better than the optical disc. When a CD is ripped, the error correction codes from the physical disc are removed so you just have the pure file to stream. The file can then be streamed from memory, not in real time from storage. This is said to sound better, and someone once sold a memory player, before SSDs and bigRAM and hifi player software were around. Nowadays I think they can all play from memory rather than disk. Lastly, the connection from PC to DAC might be asynchronous USB, which can reduce jitter, compared to potentially high jitter in the CDP. But CDPs being married to DAC in hardware can be tuned to reduce jitter if the mfg is jitter aware and knows what to do. Long way to say, "It depends... on everything..."
The best reason to use PC source is the digital content from the net. And the convenience of selection music from the network, and programming 5 hours of music to play in advance. All beethoven's Symphonies set to play in order, you don't even have to move. Better go potty first.
ewwww
