What's the flow from the PC to streamer/server...or do I have to move music off the PC?
How does Dave pick up the signal from that?
an independent streamer will either have its own storage (like aurender N100H or N10) + ability to stream from Tidal and qobuz, or without HDD (like dCS Network bridge) but will stream from local NAS and has the ability to play music from Tidal/Qobuz as well. there are so many options out there for Streamers from the very expensive to the cheap. with various preferred method of providing digital out: some have USB only, others have the whole lot from AES, optical, coax and BNC for you to choose your favorite. most of streamers will offer you some sort of app control via a smart phone or tablet. some could work with roon, others will only use their proprietary app like aurender. talking streamers is a huge topic with lots of brand/options/opinions.
the selection of streamer does actually affect your sound to its core - I quit on the idea that bits are bits long ago. each streamer will have its own distinct sound signature. wither its leaning to bright/warm, dynamic or laid back. you can investigate more on the internet - many reviews, discussion threads. however, the one thing I'm certain of, almost any of those would be better than a PC or a laptop.
main things in my opinion while deciding which streamer to get;
-how it "sounds" like as per what the majority of users say on forums, reviews. if you can demo before you buy, that is the best way to go.
-how are you going to control music play back and track selection etc. is this app/method reliable or finky?
-if it has internal HDD or will connect to your NAS where your music is stored
-if you use roon, will it work as core or end point only
-does it have some sort of high end clock for lower/zero jitter? this option is usually costing much more money. but it makes a difference. mostly you will connect your dac via Spdif (BNC, Coax, Optical or AES) to take advantage of the high end streamer clock. USB will depend on DAC clock, which is pretty decent in DAVE. the streamer will give you the benefit of much less noise/jitter and blacker background still.
-how good is the power supply portion/ have they done their best to isolate the audio out from internal noise etc.
I read that DAVE is pretty resilient to bad power and noisy signals. but I can tell you with confidence, it still gets affected. if you have a DAC of such high caliber like DAVE, you owe to yourself to try a better signal into it.
personally I use aurender N10 into my R2R DAC via AES. but a friend of mine owns DAVE with N10 and he is very happy using an ATLAS Marvos BNC. another DAVE owner I know uses dCS network bridge with same ATLAS cable (phenomenal cable for the money by the way. terrible while breaking in thou). good synergy for both these streamers with DAVE from what I heard.
I think if you are skipping USB (personally I don't like USB for Audio - its only advantage is the bandwidth which is not everything), with DAVE you best connection to use would be probably BNC. it has more bandwidth on Chord devices generally, up to 384 khz if I'm not mistaken. which means you can stream double DSD from a compatible streamer via one cable. Rob watts favors BNC as a connection somehow i believe. also, if you plan to add an M scaler moving forward, you are pretty much limited to dual BNC between these devices. then you can only connect your streamer to m scaler via USB, BNC, or optical only. I would still choose BNC for that connection. sounds better than USB out of the right streamer, and has more bandwidth than the optical.
optical on paper looks interesting, as its using light - not electrons interaction. I have tried recently some high end, 480 aperture glass cable. it was really good sounding, but my AQ Wel signature AES still sounded better. one last thing; I wont recommend investing in an expensive AES cable with DAVE, as if you decide on adding M scaler, that AES cable will be useless. m scaler has no AES input...!
hope that I have been of help