I have to agree with @russ69. I would work with what you have until it is optimized. Judging by only one photo. The speakers look too close together, the system should be moved from between the speakers. The front wall needs dampening. You might have a look at my main system to get a feel for a set up. But I bet you can very significantly improve your system by setting it up.
I would also try out any ss amp you may be thinking about… it can be a problematic trade off.. My history has been to move towards tubes not away. I highly recommend Audio Research as upgrades… Preamp, Phonostage, amp, or DAC.