I have tried all sorts of upgrades in the electronics and not been convinced that they are better. My rule is if you have to squint real hard to hear a difference , it is not worth the money.
I have come to the conclusion that for me, there is no point in upgrading my system until I get better L/R speakers. I currently use JBL 590’s and they are great for what they are. But all these upgrades I tried cannot be heard through them.
So I suggest thinking also about the speaker situation.