Personally, I think if you’re concerned about hi-fi sound, then a proper hi-fi set up is called for.
I’ve got a great sounding DAB/CD player in our bedroom that most people would be happy with for their main listening source, but it can’t touch what I’ve got in the lounge (MBP through a DAC into Denon 4400 monoblocks into some monster Dynaudio floorstanders). As Cynic-al says, it’s not a hi-fi amp, and you’re going to be hard pushed to get better sound for £500. Not impossible, but it won’t be easy.
I guess it depends if your priorities have changed – are you after convenience and simplicity, as well as helping your son out, or do you want it to blow you away sonically?