Check into ROCK on the forum. People use NUCs as their core devices. I use an imac i5 2014, and anyhting above DSD 256 is a bit of a processing strain. Your G2 should work well. I think a few folks use them with Roon. there are some posts on that.
For DIY Roon Core I would recommend the NUC7i7DNHE (not listed on that link but is officially supported) if you’re going to have it connected to your DAC via USB. Very low power consumption, runs cool, shouldn’t hear the fan at all from the listening position. You can also put this motherboard inside a fanless case later (not too hard to do).
Your Vega G2 DAC has probably the best designed USB input of any DAC on the planet (at any price…). It doesn’t just feature isolation (like many other great DACs) but the way the designer has implemented the USB isolation is unique among DACs and is done properly. So you can probably connect the Nucleus Plus direct to your DAC by USB and not worry.
However… your Vega G2 is already Roon Ready! Just hookup to your router/unmanaged switch via ethernet cables and don’t worry about another Roon source and USB. Your Roon Core will see your Vega G2 DAC over the network.
For best reliability (less potential for headaches) ethernet cable to router/unmanaged switch is best for hooking up Roon Core and your Vega G2. If you have this option for ethernet cable already available, do this and don’t spend any more time thinking about WiFi.
For Roon Remote Control via your iPad, WiFi is needed and no problems of course.
Depends what DSD sample rates and exactly what convolution?
@danny can help more about the Nucleus Plus capabilities though.
Better to do it before the DAC, instead of after the DAC. The right DSP can sometimes help with SQ performance. DSP can also harm if not done properly but only you can say after listening before and after DSP.
You have multiple options for DAC inputs (for Roon) - USB connection to Nucleus Plus OR just ethernet connection to router/unmanaged switch.
If you connect the G2 to router/unmanaged switch via ethernet cable, your Nucleus Plus (also connected to router/switch via ethernet cable) will see it on the network - so you don’t even need a USB cable to connect Nucleus Plus to your DAC. Your DAC already is ‘Roon Ready’ over ethernet.
USB cable is only required if you didn’t want to use the ethernet input of your DAC - but I would just use ethernet input if I were you.
RAM is easy to change. But Nucleus Plus already comes with enough RAM for the future. @danny knows what is coming over the next few years for Roon, so I would trust that Roon include enough RAM with their flagship Roon Core. I wouldn’t worry about RAM if I were you.
Like I said earlier though, it depends how comfortable you are with DIY. Not everyone is comfortable with that, so the Nucleus Plus is a great option for those people.
I also have a fanless sonicTransporter i7 that @Speed_Racer linked above. I’ve since given it to my old man (dad) and it is very quick (running both Roon Server and HQPlayer Embedded for up-sampling to DSD512). It looks like the new model is the 6 core i7-8700.
No because your Vega G2 has a Roon Ready ethernet input, you don’t actually need to use USB at all for Roon. The sonicTransporter will be the Roon Core and will see your ethernet connected DAC over the network. See my explanation a few posts above - you have the option of either the USB input of your DAC or the Roon Ready ethernet input of your DAC. For Roon, no need to use both. Just use ethernet.
The sonicTransporter runs Roon Server as well as other apps, running sonicOrbiter OS. Running Roon Server, it will act as your Roon Core. You can search to compare i7-8700 performance against the various NUCs. It’s quick.
Nucleus runs Roon OS - developed by the Roon Team. You can run Roon OS via the Intel NUC DIY option too.