Balance

A power supply or external DAC on the NDX would be sensible if this is your main source.

I actually removed the dac as it just didn't feel right. Too digital too slow. Too much detail without passion.  Am thinking of going the whole hog and getting a 555ps. Although would an nds and xps2dr bw to front end weighted. Nothing wrong with my system just can sound a bit shout on some recordings. Think the 250 has exposed a weakness up front

The DAC sounds very good with a 555PS. Nothing like the XPS2. Detailed and musical with superb timing and grip. Still won't beat the NDS. Will sound very good indeed on an NDX though. 

I'd recommend home auditioning a 250DR too.

G

Power supply for the source. XPS DR will be a serious lift. 555PS  DR even better if funds allow!

I have a similar system to yours, also running the NDX bare and I am delighted with it but also have thoughts from time to time of what would it sound like with a PSU on the NDX or with a DAC in place.  However I don't find my system deficient in any way so am resisting the urge to investigate for the time being!

As Graeme says the 250DR could be worth checking out, I haven't done the comparison as I changed straight to it from a NAP200 but there seems to be almost universal praise for the 250DR vs 250.2 and you could have yours serviced and upgraded.  The 250DR is a wonderful thing.

I know source first rules, and is a very sound way to build a system but it strikes me that you are close to the point where you may need to validate whether your speakers are showing the best of what your system can give.  I found in my system that changing speakers up to Kudos S20's from Spendor A5's (with Kudos C20's in between) has brought great gains, suggesting that the source and other components have more to give.

I'm only in Poole, so not too far away, you're welcome to pop down for a listen.

Richard

I agree with some others here, as good as the NDX is, and I have owned mine from since they were first launched, its DAC output stage  in my opinion is not a particular strength, and can be bettered significantly by using a Naim DAC with 555PS, or certain non Naim DACs... I think given the rest of the system, your NDX output stage is possibly a performance limiter. Interestingly I don't find external PSUs on the NDX hugely change its performance, but they do change its tonal balance.

Simon

Thanks all. After having a chat with my dealer and reading your comments.

1. I think a 555ps will be on the cards

2. Followed by an nds

However first I'm going to enjoy my system and Dr my supercap this summer and the 250 at xmas.