Source recommendation

My system consists in the following:
Bel Canto Pre2
2 Bel Canto M300 mono-blocks
Cd Player Marantz CC4001
Speakers: Proac Response D2
I am interested in upgrading the source and would like to receive recommendations on how to do so, if buying a new CD player or a DAC.
In the case of a DAC which one will have a better synergy with the rest of my system?
I listen mainly to jazz
Thanks