Thanks i have changed my profile. Many moons ago at my dealer we added a second 555 dr to the nd555. It just made everything sound more natural, a better sense of timing seem to make the music hang together better. So with a holiday cancelled i started looking for an ex demo, rang Signals and one available…so went with it.
At home what i was not expecting was a the improvement in the bass control…which i thought was on the money anyway. The new Dylan album has a long track “ murder most foul” which he underlines some of the lyrics with very deep bass. The second psu really tightened that piece of music. It has taken the nd 555 a couple of weeks to come back on song even with an ex demo unit. Everything just sounds better, not night and day, but just sounds right.It is as somebody described the icing on an already nice cake. No going back now for me.
Wish I hadn’t asked…… 
Do yourself a favor and join the camp of 2ps, life is too short to not have some guilty pleasures…
Or save yourself some money and trade it all in and get a rossini
This morning I swapped my PS555DRs round. I now have the newer unit on the lower shelf with the older one above. I also feed digital from the upper PS, which is different to what Gary found. I didn’t know what to expect, but it’s surprisingly different. It’s only been a short while, but it’s definitely different, possibly better - only time will tell. Something to try for sure.
- My very subjective thoughts, and first impression, about the ND555 with two 555PS DR.
Being a pragmatic person and knowing that, after a certain level, improvements in sound quality often tend to reach an asymptote, I was not expecting tremendous changes. There is no such thing as magic…
And to be honest, I was not totally satisfied with the ND555… Fortunately, the recent firmware updates did really well by allowing more details and a deeper stereo image.
By adding a second PS I was expecting it to improves things a little further, but not much.
So, really, no great expectations here.
I couldn’t be more wrong… not about the magic, of course
As we use to say it the Vaud Canton (Switzerland) I am “disappointed favourably”, which means the surprise is a delight!
In the context of my system, the change is unexpected and, I dare say, astonishing!
But, how to describe it?
I’d say it’s more or less like shedding some light on a nice and well-known painting.
Colours are more vivid. Curves and forms are outlined.
Everything, of course, keeps at the exact same place but at the same time seems more separated. Every detail in the painting is sharpened, but without added contrast.
That added light makes the background of the picture more vivid, but without bringing it to the foreground.
The overall feeling is an increased depth all over the painting giving the impression that, that flower over there is behind that particular tree on the left.
Details previously hidden in the background are now very much visible.
Highs and lows are clearly improved.
Edginess or graininess I could sometimes hear is gone. Highs are now crystal clear (but no magic here, edgy recordings remain edgy).
Double-bass attacks are sharper than ever, giving me the impression of having less bass (and more bass at the same time – strange, isn’t it? This is hard to describe).
Recording venues are much more perceptible/apparent (when present in the recording) which adds some airiness to the presentation. That airiness really is THE big difference.
Microphone placements and the sound engineer’s work are much clearer (this can be disturbing with some recordings).
Another nice thing is being able to “see” the violinist moving around the microphone (this was audible previously but obvious now).
Everything is the same but very much different!
All the above description is especially true with complex music like violin or piano concertos and, of course, symphonies!
The micro dynamics increase benefit a lot to grand ensembles, but to solo instruments as well.
The piano, when well recorded, is a delight. It’s not a metamorphosis, of course. But attacks, decays and timbre are clearly much better.
You get easily tempted to listen louder!
A totally unexpected surprise is cembalo. I’m not a huge fan of the instrument. But know pretty well how it sounds. My father-in-law has one, so I hear it regularly…
On that particular recording, the cembalo sounds simply astonishing! Jaw dropping, really! It sounds almost like a real one (and this is not a hyperbole).
My wife, who usually isn’t that expansive about hifi was totally dazzled. She knows better than I do how a cembalo sounds (she had to hear/suffer it almost daily during her childhood… 
).
These are the albums I referred to for my first impressions:
As for less acoustic (more engineered and/or amplified) music like jazz, folk or rock, the difference is very much present but not as much as with well recorded classical music. Or, I wasn’t able to find a lot of well recorded/engineered albums…
The following non classical albums are nice and benefit a lot of the added PS:
- Conclusion:
Adding a second 555PS clearly takes the ND555 to another, unexpected, level.
Does it compare to sources “at up to twice the price”, as stated by HiFi Critic?
Well, this is hard to tell. I had the opportunity to audition the Soulution 760 DAC (which is twice the price) with Soulution 711 amp and Magico S3 MkII speakers (the ones I have). It’s hard to compare, both systems are brilliant. The Soulution system is incredibly airy and layered. The Naim system is very resolving and has a tremendous grip on bass!
In my opinion, the ND555 with two PS is really a different beast. I dare say it became exactly what it was supposed to be: an outstanding streamer/DAC.
So, is a second PS worth it?
Yes. Very much so! The second PS is, in my opinion, a wonderful addition.
Well Thomas thankyou. I have never been able to put words together like you to explain the musical experience i am hearing…very well done and so pleased you are enjoying the new addition😁
I am happy you like it as much. I already thought with your preferences in music you would benefit a lot of the 2nd ps. It also enables to amplify benefits in the earlier chain, NAS, Ethernet and switch…
I listened to a system with a Bartok on Saturday; sounded lovely. Into a Gryphon amp.
At the price, the Bartok is a bargin really.
The rossini and even more so with the clock, is just astonishingly good and well beyond anything else i have listened too in the dac/steaming world. Plus its future proof to a point with its its upgradeable chip set, which is nice to know going forward as we all hate lossing thousands when your gear becomes yesterday news
Nice choice of music
I hear this as the purity of bass improved - the fundamental note is not spread-out into distortion harmonics surrounding and blurring the note and its timing. There is greater power - energy is retained where it should be in the produced notes as they are played and the rhythms are more time-accurate and musical - they convey the Artists intent with their flow and pace drawing you to them…
A ‘small’ point or aspect of your nice summery of differences perhaps - but how many ‘small’ differences mount together into a rather large difference, in not normal basic HiFi parameters, but eclipsing these into the background where they really belong - and offering-up real musical insights and connection to the performance.
It is nice to experience these things. 
DB.
I just got all of the above on my NDX2/XPSDR with the addition of an Isol-8 PowerLine Axis and 3 PL-Lites in place of an old Hydra.
G
Shouldn’t have come in here, should I? Anyway I am safe. Not enough shelves to add a second one 
How was it, FR?
Jim, I didn’t remember that post, and it was not mine. Is there a bug somewhere?
Thanks Richard. So my memory was good. It was Michael original post. But I don’t specified it enough clearly, like in black characters or big characters.