Advice on upgrade

If you haven't 'tweaked' the system with AC conditioning, isolation, room treatment, etc...I would do those types of things before changing out components. I've had a couple of systems similar to yours which benefitted greatly from modest priced 'tweaks'.

depends what you try to get from upgrade...
changing speakers may give you the most roi.

Modest tweak: Ear wax removal...from your ears (if there's ear wax anyplace else...well...that's just creepy).

removing ear wax may damage your ears. it usually falls off on its own

But what happens when the ear wax is the size of a ping pong ball?