There are some CD players that will play MP3s. I don’t know what process they use because as far as I’m concerned why not use wavs! MP3s use less space but do not sound as good as wavs IMO. Plus I burn wavs so they can play on anyone’s CD player.

Back to the initial discussion, another factor is what is the difference between your computer sound system (amp/speakers/settings etc) and your stereo system. I see you have listed your stereo system but not your computers. Listening an a good computer system (pro amps and near field monitors) can sound different when listened through a home stereo, even a good home stereo.

Plus as Matt has indicated are you burning a data CD containing MP3’s or are your converting a MP3 to a CD wav file? Check and see what the file type is on the burned CD. IF it’s a CD wav file then some kind of conversion is being done to your files.

Whenever I get something stuck in the back of my throat, I dislodge it by drinking a beer.
It's called the Heineken Maneuver.

64 bit Win 10 Pro, the latest BiaB/RB, Roland Octa-Capture audio interface, a ton of software/hardware