Hi,
Do you think it might be a room treatment issue before buying stuff? Room treatment goes a long way and speaker placement matters. Have you ran your receiver's calibration with its microphone? Is it just that the treble seems too tame for your liking? You may want to explore this before buying a new receiver or power amp just to find out it sounds nearly the same due to the above.
Otherwise, you could just get a power amp (class A maybe); you already have a pre-amp for your turntable, so to add bluetooth back you could just get a dongle.
Very best,