Two DACs for one system?

What @jond said. The DAC in the Node 2 is pretty good all by it's self but certainly can be bested if you want to spend the money. I've not heard your CDP but no doubt it can also be bested with an external DAC. I would recommend becoming very familiar with the sound quality of your newly acquired Node 2 (?) before acquiring a new DAC, you might be pleasantly surprised. I purchased my Node 2 back in April btw .. love it. Enjoy.

I agree that an external DAC could better playback from both units. To what extent depends on your system. Please provide more info on your system. 

OP's question is a bit ambiguous but neither the Node2 nor a CD "player" require an external DAC. That been said, I guess one could argue that these devices could potentially benefit from adding an (external) DAC between them and the preamp. Even if that were the case, you'd need separate DACs for each if you want to be able to switch sources using the preamp vs. swapping cables.