PSU upgrades for nDAC/SN2 system

Hi all,

I have a bare nDac connected to SN2 in my system with MA Gold 200 5G speakers and Innuos Zen Mini Mk3 as a source. I want to add a third Naim box in my system as a PSU upgrade. I don’t have a fixed budget but look for a long-term advice.

I’ve read that the nDAC performs best with CD555PS, but I don’t think it will fit my budget in near future. I lean more towards adding XPS or XPS DR, however I’ve read comments that for some people the XPS brought almost no gain to performance and they felt a big difference only when adding the 555 PS. Is this common and does it mean that unless you go for the 555 there is no point buying external PSU for the nDAC? I don’t want to spend 2000-3000 pounds (for XPS/XPS DR) for something with questionable gain in improvement. Also I’m interested whether XPS DR bring noticeable improvements over the old XPS paired with the nDAC in particular?

In addition, I’m thinking of buying Hi-Cap DR to my SN2. Do you think adding XPS to the nDAC and Hi-Cap DR to the SN2 would be a good match to my system and reasonable upgrade as a whole?

Best regards!

I would subscribe to that camp (as in 555PS is the one to go for) - that’s what I’ve used.
I actually found a pre-loved 555PS non-DR to be a more suitable power supply. Those can be found for decent amount.
I had mixed feelings when XPS was connected.

HiCap DR on SN2 - a very good addition.

If there was only room for one power supply right now, I would go for the HiCap (so much for the ‘source fist’ :))


I haven’t tried a 555 but I can tell you imo adding any PS makes a difference. There seems to be a bit of snobbery re the XPS and the 555, you’d expect the later to be better as it’s considerably dearer but to suggest the XPS (especially DR) makes no difference is simply wrong.

I’d be very surprised that Naim would make/sell a PS that wasn’t an improvement.


I’m in the same position, wanting to take my nDAC a notch up with a PSU upgrade (555PS DR or not), is beyond my reach. Though discontinued and a step below the XPS, I’ve read that the XP5 XS gives about 80% performance of an XPS 2. Perhaps @MDS can chime in.

Pete, Adam was referring to the Ndac upgrade, not 272, as regards of xps vs 555ps.
Have a good day. Time to sleep for me. Just finished Devs.

Yes, I know but I was talking about power supplies in general. Pleasant dreams. :+1:

Agree Pete - I added an XPS 2 to my CD5 XS/nDAC and WOW what a difference

Have you connected the CD5XS to the nDAC and used the XPS to power the DAC.

Yes, it gets rolled out in the NDX2 debate as well. But let’s remember the 555 is well over twice the price of the XPS DR, and if paired with the 272 or NDX2, only half of the 555 is being utilised. So it may sound better, but as an investment its out of context with 272 and NDX2 in my view.

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That’s why it’s labeled 555.

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2nd hand 555PS price has come down a lot. It’s worth it. Go for it.

Ndac/XPS2(non DR) < kind of disappointing. You miss nothing not going XPS2 path according to me.

Sure if you can get one at the right price grab it. :+1:

Yep - as done by my dealer Harry - great man

Are you in Sydney, my guys name is Harry.

Sure am Pete - been dealing with Harry and Norman for 30+ years. What service and so knowable on all things Naim

I’ve been on board for over 25 years. They’re legends.

Indeed - best on the planet

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There’s a school of thought that says that a non DR 555 works better on the NDAC than the DR version. The Naim DAC seems to be the only device that attracts this viewpoint.

A used non DR 555 should cost significantly less than a new XPS DR and not much more than a used XPS DR making it quite a bargain for your needs. Service intervals for the 500 series are also 15 years rather than 10 for classic.

If you ever purchase a Naim streamer then you can always re-purpose the 555 and even have it DR’d at that point.

Thank you for your comments!

I now that the old 555PS was discontinued in 2012, so if I get a 8-9 years old PSU it might be a bargain if the service interval is 15 years. Just out of curiosity, do you know approximately how much a recapping of the old 555PS might cost?

I actually use a serviced non-DR 555PS on my NDX too. Prefer it that way (555PS DR is used with my NDS in another system, so to answer the question: yes - I have tried both combinations).

Servicing a 555PS is not that expensive - several hunderd pounds, if I recall correctly. Best done via Class A in Sheffield.