Assuming you have a 5.1 or better A/V Receiver which I prefer to play my CD's too, albeit I listen to it in 5.1 Natural Stereo Sound, I've made 2 CDRS at the same levels & connected 2 CD Players to my receiver using the same cables. I switch each player on & off on the same track of song which I play a segment from 20 -45 seconds or so. I've noticed total differences always, it might help that a decade ago I produced records for a while & notice differences in tones etc,. that might not be apparent to someone else, as my ears are kind of trained for this, especially when I mixed & mastered rock recordings. Unfortunately, or fortunately if that is the case, every single much more expensive modern CD player I've tried that was under $2,000 list price, still could not compare to the sound produced by my Pioneer PD-59 CD player which I think listed for around $550 or so when it was on the market a decade ago & shows up on Ebay for between $200- $350, every so often. The biggest difference I notice & I guess is my prejudice, is the sound tones- my Pioneer to date has produced the warmest, sweetist natural sound & the other players sound colder & harsher in comparison. I listen to mainly 60/70/80's remastered recordings & there's a certain type of sound I expect which I don't hear in most modern recordings. Interestingly enough, my niece who's 25 years younger then me, prefered most of the other CD players to my Pioneer, as she's use to a different type of sound. The thing that freaked me out the most is the biggest difference in audio quality was between my PD-59 & my somewhat state of the art Harmon Kardon 31 DVD player. CD's on the Harmon Kardon sounded way too bright in comparison to the
PD-59 though DVDs sound great on it, including music ones.