Yeah, I think the CD player naming convention works the same way as for MiniDiscs:
XE/JE - entry level models
XB/JB - QS models
XA/JA - ES models
The ES models follow a different pattern but for XE/JE and XB/JB the following applies:
9X0 is higher in the range than 8X0, which is higher in the range than 7X0, which is higher in the range than 6X0 > 5X0 > 4X0 > 3X0 > 2X0 etc
X80 is newer than X70, which is newer than X40, which is newer than X30, which is newer than X20 etc
Amplifiers of the same era were TA-FE / TA-FB / TA-FA.
Cassette decks were TC-KE / TC-KB / TC-KA.
Analogue tuners were ST-SE / ST-SB / ST-SA.
CD players are CDP / Super Audio CD players are SCD.