Shame, middle was right where I liked to be audio equipment wise. Ive had my Onkyo receiver for a long time, guess when I do finally replace it I’ll go high end.
Consider trying a current generation class D amp first. I switched to the SMSL SA-50 from a pretty decent Marantz. The SA-50 sounds MUCH better for a fraction of the price, and it's tiny and uses very little power.