Hello experts. Is it redundant to install a DAC between a CDP and my pre-amp because the CDP has an internal factory DAC?
Do you do this only for a CD transports? Thanks in advance for the comments and experiences shared.

Onkyo SACD, AricAudio 3.7, C-J Sonagraphe 250
Yes it is redundant your cd play has an internal DAC. You could add a DAC if you thought it might improve performance but it is absolutely not necessary.
First you would need a digital output from your CDP. Then it all depends on which DAC is "better".