Maybe moving from Mac

[mansr]

I don't know how the built-in sound outputs compare, but a decent external DAC will outperform either by a good margin.

[mansr]

it will cost $$ to buy another Windows machine, but you already own the Mac

 

do you want to spend a tiny bit more for better SQ or what?

 

if the former just add an ext. DAC on to the mac and keep it - dunno if an iFi would sound better or not

Eventually the Mac will need replacing, and at that point a regular PC might be cheaper. In fact, perfectly competent PCs can be had for much less than the price of a Mac. In the end, it comes down to what you need from a computer, and the cheapest ones might not deliver, but with PCs there's more choice and thus a better chance of finding a good fit without paying for features you don't require.