You already got a quiet decent system. You can do better, but the question is, is it needed.
The (relative) weak point in your setup is the amp (and build in dac). Not that the yamaha is really bad, but it can be done much better for not so much money also. Some will also bring the lack of dsp into play, but that is something complex that most don't want to bother.
But if you do, replace the amp with a high rated amp (ncore or purifi based is good, but there is more) and a dac with dsp (like the minidsp flex) with room correction. That may make a difference but can cost a few thousands. So it's up to you to decide if it's worth it.
But again, you got a quiet decent system toghetter, so if it fits your need, no need to upgrade.You already got a quiet decent system. You can do better, but the question is, is it needed.