How can I make Naim 272 Preamp/Network Streamer and Mcintosh C2500 work together?

Looks like you’ve jumped the gun. I think a more pertinent question is whether you want to stick with all Mcintosh or Naim. If the former which appear to be the case, then the 272 needs to go. Something like an NDX or NDS will be more suitable but you would need to check compatibility with the Mcintosh C2500 preamp.

FWIW a Naim preamp works best with a Naim amp and power supplies. The 272 is often matched with XPS or 555PS(for ultimate sound quality), together with the matching power amp either the NAP250DR or 300.

Audiotroy,
Why doesn't Naim list 272 as compatible with XPS 2? 
I use line out on Naim, will XPS DR still make a difference in sound?
Will Burdy cable work going from XPS DR to NAIM 272?
Do you take trade ins such as my Naim 272 for NDS? How much will i lose?

I've been looking for the XPS power supply and it's ridiculously impossible unless buying overseas, but I see Teddy Pardos XPS. I know you can't be bias but can you tell me why I shouldn't buy TXPS or help me find Naim XPS?

First you may want to listen to the NAC 272 as a preamp it is shockingly good and you may find it better sounding then the Mcintosh. 

Second you can take the line level output which is fixed and viola you can listen to the sound of the streamer as an analog signal without volume which would be perfect for connecting to a preamp. 

We are Naim dealers so PM us if you have further questions.

Dave and Troy
Audio Doctor NJ