Well, what you are saying is interesting. But this is not what Naim claims themselves.
I called them up and they told me that the new DR power supply is built to be superior to the previous PSU’s, hands down.
When I told him that the old PSU sounded better in my system repeatedly - he did not have any explanations for it.
Naim claims superiority in SQ, and measurement for the new DR power supplies. Otherwise they would not build it.
Okay, in that case buy a 555PSDR and enjoy the musical benefit that it brings. I upgraded my 555PS to the latest DR status a few months ago and appreciated the result.
Or trust your own ears.
It is nice to have the choice!
Dont get me wrong. I totally agree with you!
I don’t think the DR version sounds as good as the old version, so I’m gonna try to locate an old PS555.
I had the chance to try it with several Naim units.
The results were always the same ==> PS555 sounded better than DR.
I totally agree with you on the fact that one should trust the ears.
After all, we are listening to music, we are not measuring electronics in the lab.
If you are in the UK, one of the well-known Naim specialists has a second-hand ND555 for sale on their “Latest Pre-Loved Stock” section, it’s 2006, so you might think about getting it serviced. They give a 12 month guarantee on all their stuff.
Thanks for the info.
Well, I am not in the UK, but I live in EU for now. Do you have more info on the unit?
2006 vintage, serial number 227xxx. I’m not sure if I can tell you the store name without breaching house rules, google naim audio St Albans. A call to the store will get you good information, they are Naim specialists and will tell you what they know about the 555PS. I’ve bought second-hand f rom them, really good guys.
I hear you.
I found it and I know the store. They are a pleasure to do business with.
However, it appears the unit is gone.
Ah sorry, it was still on their stock list.
Not sure what the 555dr does for an Ndac but the difference between an xps2 and 555 is huge. Upgraded to the non 555 fed by a Moon Streamer and its very very good. Only have one piece of DR in my system which is a SCDR on a 252. Non DR 250.2. Dunno what difference a DR 250 or 300 would do for me but the non DR 555 is a bargain sh
When a used 555 hits the market one has to be quick, I purchased my used 555DR from Australia and it arrived 4 days later!!
That appears to be the general consensus!
Hard to find these 555 PSU’s 2nd hand.
Found and old PS555, but he wants a lot of cash for it 
I have seen a lot for sale around the 2.2-2.5k mark on eBay. They seem to come in waves though. In the end I just bought 2 new DR ones as I didn’t think the difference between used and the June promo pricing was worth it for me. Being an original owner has its benefits like warranty, install etc.
Good point Steve.
The one I found is the non dr version (which Im looking for).
But he wants 4.5 k for it.
Im not sure. It feels a little too much
FIFY.
There are serviced, DR ones with Naim’s service warranty on the auction site for that!
Only a few months ago I picked up a 2017 serviced one for a bit over £3,000 from a reputable dealer with 3 months warranty over the Naim service (I then sent it for DR which you won’t do).
Does the factory DR process cost about £1.6k?
Yep, for a few weeks more, then it is combined service and DR.
Quite a lot of 555 available at auction, cheapest one at 2.5k …