Could I make use of a DAC with my setup?

OK, great, thanks for all your replies.  I did not know this, as I thought any input signal into the P5 preamp would go through its DAC.

This opens up a lot of things for me to think about!! :-)

And, yes, n80, I have been looking at the Schiit products, but just thought there was no way I could make one work for me.  :-)  Thanks for your thoughts about this.

Just curious was there a reason you never connected the PC to the usb on the P5?

Well, it is complicated. :-) My PC is next to a wall, while the audio rig and speakers are well out into a somewhat large room (20x25).  In the morning, I listen to my $20 desktop speakers while at the computer.  I don't power on the rig until later in the day. 

Anyway, when I would "tell" my 10-yr.-old Win10 PC that I now wanted to listen not to my desktop speakers, but to my USB connected setup, the PC had trouble making the switch-over elegantly and often (not always) sent static over the USB connection to the P5.  I grew tired of trying to troubleshoot this. 

I was told that the 3.5mm connection is high fidelity (like the USB), and this has worked out well.  The P5 has an 'AUX in' on the front panel.

The only problem is one of convenience.  I have to manually switch out the 3.5mm cable from the P5 to the 3.5mm cable of the desktop speakers when I want to transition.

My goal is to buy a laptop, integrate into my setup, and stream from the laptop.  I'm still in transition, held up not so much by lack of funds as a lack of knowledge about how to proceed; hence, the DAC question above.

Ah OK , I never tried the usb on my integrated amp I just stream through it's lan port. Thought it would have been easier to use the usb but I understand about trying to get old computers to play nice. 

Nice that your integrated amp has a lan port.