Went through parallel quest 27 yrs ago, I tried a Theta Prime, Pro Basic, with Magnavox CB650 as transport. Unsatisfied with the outcome, added a full set of Conrad Johnson Premier and VTL deluxe, both full pre/power combination. Tried 2 x Krell KSA250 and vertical bi-amp. Rotated loudspeaker of many flavors to come to the realization that room acoustic was the final frontier.
Read a lot of books and tested various passive room treatment. Still have various acoustic softwares until I came across a product name SigTech. Denis Doyle came and gone with a total of 4 units of SigTech, 1 for music room and 3 for theater, I’d learned that the combination of passive room treatment, speaker placement, and electronic room correction out weights ANY equipment upgrades in my life long pursue for good fidelity.
My humble suggestion is to look into room correction processors. Currently I’m using QEDX in three separate systems. The beauty of this is that it is a Dac, digital crossover (for subwoofer), and pre-amp. Three birds in one stone.