You can see the CD spinning when the music is playing, like a turntable. You can to remove the CD cover
If you have psone version "SCPH1001 PS1" or "SCPH1002 PS1" is better for the sound.
It'is the one that ships the famous AKM AK4309AVM digital-analog converter. It is the chip (integrated circuit) which roughly decodes the digital sound of CD-Audio into an analog audio signal that can be given to an amplifier (with tubes of course) via the audio cinch sockets on the back of console.
Others creations on internet (not me in this case) :