agree with @arcticdeth on speaker and listening position significance.
also; imaging has much to do with first reflections to the sides, behind, below and above the speakers. those first reflections will reach your ears close enough in time to the direct sound from the speaker drivers that it will smear and confuse the musical cohesion of the stereo image. yet, if you treat those reflective surfaces too much it will deaden the sound and remove energy. so it’s a balance type of thing. consider some sort of diffusion and not just absorption.
finally when you sit closer, you get more direct sound from the speakers, and the reflections have relatively less effect. so that’s a factor too.
don’t blame the amps for the room and set-up issues. once you’ve done what you can with the room, then there are amplifier upgrades that will advance the realism of your listening.....but judging the amps properly does require some degree of system tuning first.
very modest gear can image very very finely. it’s more a recording thing and set-up thing and room thing than cost of gear thing. it is true that higher investment in gear will many times be found where more attention has been given to the room and set-up. but cost of gear does not = set-up excellence.
at audio shows many times you walk into a room with the cheapest gear and it's imaging in an amazing way compared to other rooms with much more expensive gear because the smaller more modest room has a better set-up.
the actual detail and tonality and accuracy of the images can be (but is not always) more cost of gear related. but before you buy different gear, put some effort into playing around and see where it can take you.
good luck.