Naim NPX300 vs. 555PS power supplies

Given the 4000+ comments on the New Naim Classics thread, and several people directly asking the above question, I thought I should start a dedicated thread on classic vs. New classic power supplies. I enjoy reading people’s reviews and it’s certainly help me make decisions in the past, so here we go:

Today I had the pleasure of directly comparing the two:

Demo set up:

NDX2 > NAC282 > NAP250 > Kudos Titan 606s (my system at home bar the NAP300)

Firstly I listened to well known tracks to acclimatise myself to the room and sound. I instantly missed the weight and realism of drums and piano keys I get from the NAP300, but otherwise it sounded like “classic Naim”.

Next, we plugged in the NPX300. It had maybe 50hours run in, and the cable less than that.

There was an instant and obvious uplift. Lots more detail and separation of instruments. It was a very similar experience to plugging in the 555PS to a similar system some months ago (the “oh wow” factor). The NPX300 was obviously no slouch in significantly improving a NDX2. The sound became more energetic, crisp, clean and punchy, with bags more detail. The overall sound signature was familiar. It reminded me of the roadshow demo of the new NSC222, NAP250 and NPX300 I heard a month ago. I found this amazing, as even just the power supply has the “new Naim sound”.

Next we plugged in the 555PS. It also has the wow factor, but a very different sound signature. Just as much detail and separation of instruments as the NPX300 (surprisingly not more?). My current system sound very real, like you’re in the recording studio, and the 555PS just turns this to 11. There is a realism to the sound, which translates into more emotion (for me anyway).

We went back and forth, then back to a bare NDX2 etc etc.

Overall, given the system we were demoing and to my ears, I would sum up -

The NPX300 and 555PS are very close and preference comes down to sound signature. Both provide bags of extra detail. The NPX300 provides a crisper and cleaner sound. The 555PS a more lifelike/real/studio sound, which for me provides more “shivers down my spine”.

Like many have comment on the other New Classics threads, the difference between the midrange New Classics and midrange Classics is really a sound presentation difference. Both as good as each other, it’s down to personal preference.

P.s. I took the 555PS home for the weekend. I think I’m probably going to stick to the “old Naim classics sound” for now.


Thank you @richardjpaterson for sharing your impressions.

Once again, this confirms to me the incredible work done by the Naim’s team in designing the New Classic series.

They were able to maintain the unmistakable sound signature of the brand while improving or rather modernizing the sound presentation and the overall experience. So much so that the new system is very enjoyable without forgetting the origins and peculiar characteristics that have made the brand famous.

That’s why the old series should not be underestimated, as it of course maintain its charm within the same house sound signature.

I think this is not something easy to achieve: it is a perfect balance between the goals to achieve and the “maison” culture. It means we are facing a well-established and mature engineering team, fully aware of their context and highly proficient.

Well done, Naim!


The 555 in Canada is $5500.00 CAD more than the npx 300, so IMO it should be a big step above the 300. I’d like to hear more people who have compared the two.

Yes. To be honest, I wasn’t really looking at the price. The 555PS was ex dem, 3 years warranty and a lot cheaper. I would think you could pick up a new 555PS with a reasonable discount. In classic series finish the price would be comparable to a NPX300 if you include the fact you also get a powerline?

Thanks Richard for starting this thread. I am considering adding a power supply to my NDX2 and am seriously thinking about the 555PS. Trying to find a pre-loved one at a reasonable price, which may take a while.


From all the black box upgrades I’ve done, I’d say the 555PS on an NDX2 is the most obvious one. Extra detail is very easy to hear.

It’s quite amazing that the NDX2 still had so much more to give. I skipped the XPS step given some reading on this forum, although XPSs are now getting cheap so probably also worth it (<£2k second hand).

I figured if a new XPS is £4.5k, I can surely find an ex dem 555PS for similar money. I found one in the end.

You should try and demo 555PS vs. NPX300 though, if not just to add to this thread :joy:

Does anyone else find it odd that they still call it the CD555? Naim said it was designed for its top CD player, so it’s understandable that was the original moniker, but now that it’s discontinued one would think they’d drop the CD and just call it the 555.

Why ?

Are you saying all CDP’s that are discontinued should drop the CD letters

And call them what ?

Because they don’t sell the 500 series CD.

See my edited comments above

What would they do with all the pre printed stickers :question:

Ha !!!

All very weird Iain indeed

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It probably has more to do with product certification, rewriting all manuals, dealer/naim website updates, explaining the change….

If it ain’t broke……

(and it certainly isn’t, 555 is awesome. Look at the new NPX it’s got the same DNA)

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If Naim called it anything other than CD555PS they would have all the hassle of certification and approvals for it as a new product and complying with whatever regs are then current such as power consumption etc.

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Now, that makes sense

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