The Cambridge Audio 840c CD player is very sensitive to cables. With the right cables and a matching (pre)amplifier, the 840c is not thin sounding. Meridian G 08.2 CD Player is a good upgrade if you really want to upgrade the CD player. Based on various reviews, the Focal Chorus 800 series speakers usually sound a bit thin. I would recommend the following:
(1) Upgrade interconnects and speaker cables
(2) Try tube rolling
(3) Upgrade the speakers
(1) Upgrade interconnects and speaker cables
(2) Try tube rolling
(3) Upgrade the speakers