Why buy a DAC when you have a high end pre/pro?

Kjweisner: But I'm suggesting that this a DAC transfer. It comes digital out from the PC or Mac and into the Digital "in" of the processor. The Processor, in turn, does the DAC work and gives the speakers an analog feed. Maybe I'm just not understanding what the need is for ADC. Enlighten me please!
I'll be the first to admit that I am not a total expert.

I've done this for quite some time - PC digital SPDIF output to a Lexicon MC-12 digital in, which uses the internal DACs to convert to analog. Very nice and a minimal number of boxes.

I have recently changed a fair amount of gear and now have a 2-channel preamp without built-in DAC, so I will have to get an outboard DAC. But, I would answer your question by saying if you have a high-end pre/pro with quality DACs, I don't know why you wouldn't do just as you suggest.

More of the audiophile things. Sweeter midrange, depth, imaging, less congestion and so on. As always these sonic features may not be worth the price and hassle but only you know whether it's worth it to you or not.

I found that a $200 Cal labs tube DAC did all these things and worth it to me.

No SS processors or receivers currently match the quality of a good stereo DAC. I have one of the most musical ones, the Proceed AVP, and it is fine for movies, but my DAC's blow it away. Not even close. My system is world-class though, very resolving and low-noise. Completely modded out.

Audioengr: I took the time to read a review on your Proceed AVP (it was very complimentary) and one of the highly touted features was the internal DACs so I have to imagine that your external DAC must be really special.
I did start using my CDP as a transport and noticed an immediate difference (for the better) by using my Krell Pre/Pro as the DAC. I guess you start with the Pre/Pro or Receiver and then experiment from there and take note of what your ears are telling you. Budget also becomes an issue for most of us.