NDS v ND555 compare time

Very possible. It has to be handled very carefully to avoid it slipping off it’s suspension. Moving it frequently should be avoided and only done by someone who knows what they are doing. It’s really a task for two people, given the weight involved.
Really, comparing an NDS and an ND555 in the circumstances described in this thread is not to be recommended. Apart from frequently moving the head units, disconnecting and reconnecting power supplies, as described, is to be avoided.


They are not being moved or anything discontinued during testing them, as they are both running there own power supplies and matching cables. The only difference between them being one was in the rack and warm, the other cold and not in the rack.
But better position off both units tomorrow and a bit warmer might start to make more of a difference, but we will see

Quit while you’re ahead and save 10k.:grinning:


Like it lol

I have had my ND555 for 3 or 4 weeks now, which replaced my NDS. I could hear a difference out of the box, but the ND555 steadily improved over the first two weeks with one or two really quite poor days. It now seems more stabilised and I can now hear a clear and consistent improvement on each and every album I hear for the first time on the ND555. These are albums I know well, having played them many times on my NDS, so a comparison is fairly easy for me.

However it wasn’t as clear cut during the first week with the ND555 as it is now.

No contest.

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The signal earth is switchable on both units. I found the 555 needed to be the earth for the system to get the best out of it and connecting any other signal earth compromised it significantly. The plug order on the block also had a significant impact but I don’t have active so can’t begin to guess what works best with a Snaxo and extra power amps in the mix.
A reasonable test would be to have both units set to earth the signal but swap between them by muting the pre and swapping the DIN cable on the back of the pre so only one is connected at a time. Leaving both hooked up won’t get the best of either. You can use the same input and eliminate that as a factor. Cable dressing will also have an influence so mind you don’t compromise it.

To me, there is no real benefit in this rapid swapping of components. Perhaps useful to get a quick idea of what it’s like in a dealer demo, but that’s about it. I would set up the new boxes properly on the rack, level them, dress the cables properly, set the ground switch correctly, etc. Then just listen to music for at least a couple of days, not just 5 minutes. The acid test is when you put the old box back in the system, and see what you’re missing. (But don’t invite Ken Kesey round for a listen!)

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the test made by the OP is right for me. However the nd555 must sit also on a good rack.
But you can also relax and listen only to the nd555 and feel if he adds something more to the pleasure, or not. As you said.

If you can’t hear a worth while difference in your system, there is no worth while difference to be heard. That’s a valid conclusion. From my experience of owning NDS and ND555 I am confident that I could not reproduce your result in my system. If I could, I’d be £10K better off and very happy about it.

If you are compelled to fiddle I would start by removing the Melco from the equation. Try a couple of USB drives into each streamer. I would also question if a stack of 250s are of sufficient calibre to show off the strengths and subtitles of a 500 level streamer, but I don’t want you to think I’m being critical of your system. If it works in your room, it works. If the ND55 doesn’t sound up to much more than the NDS in your room/system, it isn’t. Just enjoy the music.

One other variable to take into account is the time it takes a 500 level component to fully sing after being shut down. My dealer told me to wait a week before drawing any conclusions. I thought that was way too fickle for a rough scoping audition. I was wrong. If you can keep it for a week you might be hearing it different by then.

Swapping back and forth between nds and nd555 is certainly one way to check for differences.

Perhaps more conclusive to me would be to install the nd555 and ps555dr into your rack. Run this for as long as practicable - couple of days or longer ideally. Then swap out only the nd555 for your nds. If there are any shortcomings with the nds, they should become very apparent to you on the final listen. If none, then happy days - the nd555 would not be for you unless you were particularly keen on the newer platform for things like roon integration.

Please do keep us posted with your conclusions.


Right guys, last night i decided to swap my nds and power supply over and also move my rack about a bit.
So now on one side i have my 3 x 250 amps and on top shelf the nd555.
The other side i have ps for nd555, then ps for 552, then my snazo & superline with the 552 on the top shelf.
I have left it all powered on since i got it and using my old highline but the new burndy cables, as i dont think the highline was used before and mine is well run in.
Addressed the cables at the back and just sitting back now playing a few tracks, it sounds lovely but then so did my nds, i am going to try and keep it next week to give it time to warm up and settle in and see how it goes.
But i will before it goes or maybe stays? Try the instant switch between them only this time the nd555 will be the one thats installed correctly and the poor old nds on the floor with its power supply and probably cold as well, and if that can still just about hold its own in my system then no point in keeping it, as it should then be a big difference.
My 250’s are not standard and in my opinion sound great, they have all been serviced and in fine fettle, yes 3 x 500 amps would be nice but thats not going to happen, plus its the same for the nds and my 52 before the 552 and that was a clear difference in detail, air the lot.
I know that it gets very small improvements for outlay once you get to a certain point, but after hearing all the great reviews i was once again expecting more, but as i have said i am willing to give it more time to fully sing as long as i can keep it longer, as if it was going back tomorrow then i would right now not be having it.

But things can change as i know all too well, plus i am the sort of guy to put my hands up if i am totally wrong, but i am also the type of guy that needs to be proven that its better, rather than it must be better because its new and cost loads, plus everyone says it is.

Cheers dunc


As others have mentioned - what is the ground switch set to on both streamers?

I believe that you should only have ground enabled on one of the streamers if both are connected simultaneously. So either set ND555 to Default and NDS to Floating, or set ND555 to Floating and NDS to Chassis (assuming that no other sources are connected to your 552)

It was both the same yesterday, but now I only have one streamer connected

If you want to give the NDS a fair chance when you put it back in, leave it powered up and playing, with no connection to the preamp. Then it will be fully warmed up, and a fairer comparison when it goes back onto the rack.

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If it’s this much effort to discern the NDS and ND555 then there is something wrong. At Naim’s dem it really was as obvious as a poke in the eye with a sharp stick.
I’d be concerned about the “non standard” kit…

Well just been listening to a few tracks, still only early days for the warm up for the nd555, but still not much difference as couldn’t resist complaining them, as i did think it was getting better.
I think the best way i can describe the difference at the moment is that the nds is a bit smoother, but as said very hard still to hear any difference

it’s also very easy for a dealer to give an advantage on a component rather than the other. I have already seen that .

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We already bought the thing so it sounds better, best:)

I am really impressed with it so I don’t touch my cd555, soon will try it with 2 PS!

Apart from the sound it is far better with Tidal and streaming comparing to my old 272, it is snappy and no dropouts etc…

you are not really in the topic Emre. The comparison is between nds and nd555.

Sorry, what I meant it is good:) and the new streaming platform is way better

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