Yet another question about streaming

I'd also recommend the Bluesound Node. It has coaxial and optical digital outputs and almost any DAC you could buy will have one of those inputs, almost all DACs will have both. 

I think the OP is getting confused with HT like issues, where various AVRs or processors may not accept certain audio formats.  Generally this isn’t an issue with 2 channel DACs.  They all decode mp3, FLAC, ogg vorbis (Spotify).    The DAC is the bigger determinant of the sound, but sources matter, as in every other format, so yes there will be a difference between Cambridge, Bluesound, etc, just as no two turntables sound exactly alike.
  The terminology gets confusing.  Bluesound and Cambridge are essentially streamers, but they do come with internal DACs, and those DACs can be accessed by other digital components, so in a sense they can be referred to as “streaming DACs”.  Taking that a step further, a standard computer can also be a streaming DAC.
However, in Audiophilia, products that were created with the emphasis on the streaming capacity, and have DACs that have been added as a convenience or as an afterthought, are generally referred to a streamers.  If the emphasis is primarily on the DAC, and a streamer of lesser quality has been added on, we call them DACs.
if the emphasis is equal, streaming DACs.
  As mentioned above both Cambridge and Bluesound come with internal DACs.  These may not be as good as the DAC owned by the OP,but they aren’t bad.  Particularly if the source is going to be lossy, such as Spotify ogg vorbis, the OP may not get much improvement bypassing the internal DAC of the streamer.  So if for some reason the streamer and the DAC are incompatible just use the included DAC and rest easy

Thanks this is helpful.  I'm thinking I am going to start with either the node or one of the Cambridge pieces. I'm also going to rip my CD collection, and probably subscribe to one of the full cd quality streaming services.  

Maybe I’m out on a ledge but to me a streamer (network player) with a built in DAC is NOT a DAC with a bulit in network bridge (streaming DAC.)
I ignored the PS Audio DirectStream because the bridge has no USB-A input. It is NOT a full featured player.
Start with the BluNode. You are going to upgrade anyway and it has a better player app by common consensus.
Qobuz is best now but watch for Spotify. They have a bigger library, Connect and better radio than Pandora. Start with a free trialto Qobuz.
I put my CD tracks (ripped on a PC) on SSDs and plug 'em in but do whatever feels most comfortable.
Good luck to you.

I have some experience with Bluesound Node 2i and the Cambridge Azur 851n.  I experimented with both of these and my Schiit Gungnir Multibit DAC, connected to the Freya+ preamp via XLR.

Using the Gungnir from both streamers, the 851 clearly sounds better in every way than the Node.  A clear upgrade.  I was initially surprised by this, as I thought that using the digital coax output of the Bluesound and A/B'ing with the Node would yield similar results, but the difference was quite obvious.  

For quite some time I lived with using the 851 via coax out to the Gumby, but the other day I experimented again.  I ran the 851 via XLR directly to my pre-amp to see how that sounded.  This, obviously is using the 851's DAC.  I kept the coax connected to the gumby, so I could A/B quite easily from the listening position.  To my surprise, I actually prefer the sound of the 851 directly over the gumby.  It is a clear warmth and presence to the sound.  In switching back to the gumby, it sounded a little flat in comparison.  

To add some context, I have recently treated my room with GIK products, which dramatically improved the detail of the system. It is so revealing now, and I thought it was revealing before.  As a YMMV disclaimer, I am not sure if the difference would have been so obvious prior to room treatment.

I hope this helps, and best of luck.