Best upgrade for cd player?


Want more nuance, detail, dynamics.
ptss
Don’t take offence , the very best upgrade hands down to my EMM Labs player was replacing it with a Innuos Zenith 3 server .
There are a number of reasons why a decent server is far better then a disc player , sound quality is one reason. 
An external DAC can add much, as can power cords on both. I added a Benchmark DAC 3b to a Sony XA 5400 ES and am very happy with the results.  Audioquest cords for both.