Can someone advise me , does music streamer (Roon End Point) is really matter if …
a) I am only use Roon Software /Apps and not music streamer apps,
b) I am using external DAC and not usng music streamer build-in DAC.
In such case, can I use Roon Core such as Intel NUC i5 as bridge as my music streamer , then USB output to my external DAC and then to amplifier/speaker?
Yes you can and it will be fine.
Thanks mate, that’s save me a lot and i can use the $$$ for full Roon subscription 
People will argue about this one.
I would at least say that you should optimize the rest of your setup before worrying about the streamer.
Your NUC will be fine.
Hi Danny, thanks for your reply.
Actually I have owned Aries Mini, I have a great interest to look for “new streamer” such as Node2i etc. Having think of digital output (USB) from Aries Mini and/or NUC i5 to my external DAC, it should not make any difference “digitally” and logically.
After 15 year, I have optimized lately my audio setup with new Accuphase E280 integrated amplifier, ATC SCM11 and Denafrips Ares II.
Just think of should I upgrade my 4 years old Aries Mini.
I personally have a Stack Link II streamer, which I am happy with. I got it mostly for form factor-software reasons. It sounds fine.
I don’t know if it sounds noticebly better than other devices, or just the same. I’m not really interested in the comparisons.
Really the only way to determine if a streamer will make a difference in your setup is to try one. Personally I have a few Lumin’s in my setups so that the mrs can stream to systems with Spotify which she likes to use, but she does use roon too.
They should not make a difference in terms of bits, but electrical noise can leak from a USB source to a DAC via the USB cable and affect the DAC’s analog output somewhat. Most likely there won’t be a clear difference between NUC and Aries Mini, but since you have both, why not listen to both and decide?