Out of idle curiosity I was using the compare function on the Naim website to compare the 555 streamer with the 333 version.
As far as I could see the only real differences was the XLR analogue out on the 333.
So, to ask the dumb question, assuming I have not missed the blindingly obvious, why the circa £8K price difference between the two?
Thank you.
Kind regards.
Roger
I think the price of the ND555 also doesn’t include the power supply; at another £8k or so. It does sound pretty amazing though…
The price of an ND555 is indeed significantly higher than the 333, even excluding the power supply which is built into the 333. Pay more for less!
The ND555, and a handful of other higher level boxes, have their circuit boards mounted on heavy brass plates with sprung suspension, a higher level of selection on component quality, and maybe some other under the hood features. Whether that’s worth the significant extra cost is a matter of opinion. When it was first released I thought it sounded very good indeed, but to my ears nowhere near enough to justify the asking price compared to the lesser sources (NDX2 at the time.)
There’s also a Faraday cage inside the Nd555.
Isn’t this a bit like asking why a Ferrari costs more than a Skoda. After all, they both have a wheel at each corner….
I think one of the problems you run into when making these sort of comparisons is what comes after the streamer/power supply combo’s you are comparing. The more transparent the system then the more you notice the differences. I remember the first time I heard my ND555 with two power supplies, it was a total revelation.
Not quite, as I assume the comparison the OP looked at suggested that in your analogy the engine, gearbox, number of seats and several other things were the same (including Ferrari engine), but maybe didn’t mention suspension and seats, nor body shape.
Should rename this forum
analogies ‘r’ us.com
I did say ‘a bit’…. 
The product compare function on the NAIM website is pretty worthless. The two products are light years different (beyond the balanced/XLR outputs).
There are also differences in DAC chip used, the 333 uses the cheaper Burr-Brown PCM1791A (edit), while the 555 uses Burr-Brown PCM1704U-K resistor-ladder DAC chip.
How much do they both cost per pcs in quantities of say 1000pcs?
Its so low as to be immaterial to the final retail of the unit., I think the problem is lack of supply, I know the 1704 has not been in production for a long time. They probably would have used it in the 333 if they could.
In performance? I wonder how my NSS333 + 555PSDR would compare to ND555 + 555PSDR. Would be interesting to see (hear). The combination sounds mighty good in my system and my former NDS is now asleep.
Naim stated, when launching the 333, that this inferior dac chip was chosen because it sounds better in that implementation.
Is it true or just marketing, I don’t know.
Yes, I’m told it sounds much, much better in the way Naim use it than if just the chipset was fully utilised.
As for the PCM1704K, I know Naim stockpiled as many as they could, but that would only really be enough for ND555 and service needs.
333 and 222 doesn’t use PCM1719A as said above. This from Steve Sells , Tech direction Naim.
They use the PCM1791A. It appears that “PCM1971A” and “PCM1719A” are just typos of PCM1791A.
Maybe edit them to minimise confusion 
Accepting the above posts are talking about the PCM1791A DAC chip this suggests to me that the DSP to oversample may have changed from classic products to NC - otherwise why use PCM1792A chip in NDX2? This may bring NSS333 closer to the ND555 