I've had a very "good" sounding system for over twenty years. In the recent few months, it has become to my ears, a "great" sounding system merely by replacing one component-my preamp.
It cost more than I usually allow myself to spend on any particular component, though wow, what a difference it's made.
Audio is an interesting hobby, so many variables. For many of us, it takes a bit of good luck to finally get to the goal, so I wish good luck to those of who may need it.
Regards,
Dan