RCA to RCA will work fine, and if you already have a good quality cable I would use it.
If you need to buy a cable I would buy an RCA to DIN. I haven’t used a Node, but with other non-Naim devices that have RCA connections I’ve always found that using the DIN connection on the Naim box gives slightly better results.
I am using NAC 202 as pre amplifier.
Can I connect Bluesound NODE analog output (RCA) to NAC 202 to that RCA connection that I have marked with this red box (AUX) ?
Now, I am using DIN Connection to connect my CDX to this NAC 202 (CD).