Here’s an update regarding the possible reasons that most CD, SACD, and DVD players (95 to 99%) play laser read media out of absolute polarity. Previously, I stated that it’s very likely that the analog to digital conversion of the analog eye pattern of the disc’s digital data is inverted and now I’m adding that a data inversion may also be caused by the digital rate converter. If either the analog to digital converter or the sample rate converter inverts polarity but not both, and the component’s designer maintains the electrical polarity of the data stream through the player’s outputs (per AES protocols because they aren’t aware that the data stream is inverted) that might help explain why the relative polarity distribution of CD playback isn’t 50-50.
George S. Louis, Perfect Polarity Pundit™