I recently got the Audioengine A2+ speakers to pair with the Mac Mini I plan to purchase in the future. Audioengine makes a DAC as well, but reviews I've read suggest to not use it with the iMac (my current Mac), since the built-in hardware of the iMac is pretty good. Not much of a difference is noticed by adding a DAC to it. How is a DAC with the Mac Mini 2018 though? Worth a purchase? Big difference in sound quality?