@kijanki Thank you for the response. I enjoy reading your replies since you seem to understand electronics better than most on this site. Sometimes it is difficult to have a technical conversation with people who have little knowledge even about the basic concepts but they call themselves experts. I find audio a strange field... Your analysis on transmission line is spot on. For spdif I rather have proper 75 Ohms BNC terminated cable than with RCA plugs, I had an argument with somebody who was saying it is only audio, there is nothing high frequency so no need to worry about reflections, what he forgot is that reflections are caused by the rise/fall time of the edges and not the waveform frequency or data rate. Anyway, I diverted :)
Yes, yes, I much rather use Firewire than USB, in fact I still use a PC (with very little optimazation) with a PCIe Firewire card into the Weiss. But Firewire is getting old and new device of course don’t support it. I also use the Weiss AES i/f which is not too bad, almost as good as the Firewire. As I am interested in Qobuz, my next purchase is going to be a streamer, the way I see it is either fully optimize my server (both hardware and software), use the Firewire card and hopefully find some software that will support it, or buy a relatively decent streamer like Lumin/Innuos/Aurender and possibly a DDC as USB look like being the most common i/f these days. Unfortunately where I currently live there is no way to demo anything so I have to buy by what I read on forums and reviews... not the best way.