OP, a good example of a turntable to consider would be Rega or VPI
but if the room is taken care of as per the post above, I’d rip the CDs onto a mac mini or purpose designed storage system and get a good DAC, while paying attention to galvanic isolation - Schiit makes one called Eitr and it can be returned if there is no improvement
you have the best or one of the best $500 CD players from a few years ago, but that does not mean it is the best possible way to get digital sound from a CD to your pre-amp
also be sure you have the best recording/mastering of any music you care about
you have a very good system already so improvements in SQ will not be inexpensive
but if the room is taken care of as per the post above, I’d rip the CDs onto a mac mini or purpose designed storage system and get a good DAC, while paying attention to galvanic isolation - Schiit makes one called Eitr and it can be returned if there is no improvement
you have the best or one of the best $500 CD players from a few years ago, but that does not mean it is the best possible way to get digital sound from a CD to your pre-amp
also be sure you have the best recording/mastering of any music you care about
you have a very good system already so improvements in SQ will not be inexpensive