for streaming why not computer/galvanic isolation/DAC clock?

When I use WiFi rather than an ethernet connection there are no dropouts;  I assume that is better than bringing in noise from ethernte.

No.  Just, no.  You are hugely mistaken.

a mac mini is not cheap, but costs far less than high end streamers. Do people pay for the file management etc, or is the SQ better with a dedicated streamer?

A Mac Mini is cheap, and yeah, there’s a reason there are expensive streamers out there.  Just try one and you’ll see/hear why a streamer matters.

Thanks. All my stuff downstream of DAC bought used and broken over last few years.  Good way to afford stuff and find synergy. Found that for the set up I described galvanic isolation in usb between computer and dac mattered. Couldn’t discern any difference between wireless and ethernet connection.  Putting in dedicated line helped a lot, especially during the day. 

I have been trying to figure out how to best stream to my set up and looked at many alternatives, all the conflicting posts etc etc. I just wonder why one cannot use a computer with a device for good galvanic isolation, and rely on the clock within the DAC to eliminate issues of jitter.

You can. I do, I use an Intel NUC, home made Linear power supply, isolation on the digital link, Since its USB the DAC will read to buffer and re-clock anything - need it or not (well, in that case it needs it). The jitter will be exactly as good as the DAC - almost guaranteed better than any streamer, once recovered from a signal (which is imprecise and is a known challenge in super high frequency digital signals (like 100s of times faster that these silly ~ 1.5 Mbps links)

IO have an extraordinarily resolving system in the bog picture and get fantastic sound - subject ot the recording of course.

I run Roon on an older Windows 10 laptop. The sound is indistinguishable from that produced by a streamer of any make. I do use a power conditioner for the laptop, the DAC and the pre-amp. An Ethernet connection is preferable, but I use WiFi with no apparent loss of sound quality (although I do lose the internet signal occasionally).

@arhgef FOMO is a real threat. I am getting into DIY. The next goal is to find a good high efficiency speaker and build SET amplifiers - lot to learn. This post is more about trying to understand what is happening, and how these things are engineered. I think working with tube amps that sound good by virtue of their simplicity would be a good place to go.

You seem to be on a similar path as me, DIY is great. Fun ,satisfying, educational and economical. May I recommend considering a foray into a open baffle speaker using a Lii Audio full range driver such as the F6, if you dont want to risk much or the F15 if your wallet is a bit fatter. No Crossover, direct wire to amp. You can supplement bass to taste with subwoofers. Unique open airy sound with great imaging, but you do lose something on the top and bottom end.

In the amp area Decware sells the printed circuit board for their 2 watt Zen amp for $45 with instructions and parts list but you have to order the parts and transformers on your own. All in $6-700 roughly. I built it and it is a lot of fun with true SET sound. If you never built a kit before and would like all the parts delivered with a nice case look at Nelson Pass's Amp Camp kit. 8 watts per channel and a sound very like a tube amp, but solid state.  That is what I started with and glad I did. Hope this might be of help to you or someone else pursuing this sort of path.