Always experiment to determine it works to give what you like, but that said:
1. Use my suggested sequence for items that are connected via their signal paths and connect in the same way in the mains supply so that any circulating current are in just the loop between the items connected. 2. Put high current stuff - especially Power Amps on the wall socket and off the Block and place the feed to the block in the next double-socket. That again keeps the HiFi item current loops all stood-off from the mains proper. 3. Then all items that just need power but whose power is not for a signal circuit - like a pure supply for a turntable drive or Ethernet switches - put these on the following socket and also try one by one placing them onto the ‘noisy’ non-HiFi mains circuit to see if that is better or not - sometimes it is and sometimes it sounds wrong and you need it on the HiFi mains.
That is my approach - I get excellent results, but other approaches may suit other people so I’m not dogmatic on all this, but describing a methodology I use that seems to work.
My mains sequence opens-out the dynamic range possibilities and reduces coloration noise I find.
Thanks DB, a few days into trying this I definitely like what I’m hearing, though I suspect my ND555 is still burning in, so how much of a factor this may be I can’t say. I thought the NDS was wonderful (it is), but the degree to which I’m hearing a more ‘real’ representation of a musical event via the ND555 is ‘silly better’ as I recall you describing a few upgrades in the past. Single PS only here btw…
The ND555 opens things out more I find - but it also needs a little care to set it up - all the usual stuff with cable-dressing, good HiFi shelf and position - and the attention to detail with mains stuff to let it work towards its best.
I suspect I can get more from mine but I find after I reach a certain threshold of musical ability then it is good enough to then leave it alone for long periods and let it run and just use it for what you got it - play music.
Sometimes further fussing with set-up and trying different things can go into a circle so good to occasionally declare victory and enjoy!
Hificritic has just reviewed the Nd555/ with 2X 555dr. The Nd555 revisited by Martin Colloms.
I remember he preferred the nds with only one ps. So I wonder what are his conclusions now.
Don’t read it but perhaps someone could post the review here ?
I recently demoed a full SL loom at my dealers, then took them home to demo…did not workout, another story. I did at the same time try a second 555ps on the ND555, although not night and day, it did bring a sense of ease and naturalness to the music. As if it had been a little congested before, and had now opened up.
I’m planning to add a second 555PS to my ND555. Your experience of “not night and day” differs somewhat from @BertBird , @Darkebear and @Michaelb.
By adding a second I’m seeking to bring the signal/noise ratio as low as possible, which means a more detailed, airy and therefore natural music reproduction.
So how would you describe your own experience of a second PS in terms of detail retrieval and noise floor?
Recently I had some wow moments after adding another 4 bass traps and tinkering the rest of the room treatment. Improving the room responds has been an amazing experience. Best money spent ever.
So is another power supply worth it in terms of extracting more of what is actually in the recording?
It may depend on your System and you as to how you gauge 2x 555PS on the ND555. For me it was significant enough to determine that it put the ND555 into a different and higher league of performance compared to the Chord Dave with up-scaler I demoed it against - although the ND555 with two supplies also cost a lot more.
In context of my Active system with S1 Pre - it was an obvious ‘no-brainer’ upgrade. The source is rather important in not making compromises in the context of a very revealing system I found. The Statement grade kit has a graceful effortlessness and easy detail I really like - and so did the ND555 with two supplies. With a single supply it was also excellent, but not in the same league - if you compare 552 Pre vs S1 Pre it is those sorts of differences, although you got more of them with the S1 Pre change.
Also the Bass - especially low bass - is so much better rendered and handled that if your system ‘does’ low bass well in your room then you will notice that more. Better timing and start-stop of deep notes on rapid percussion and strings.
So system and you will matter - and if you can afford the cost. It is a nice upgrade in future when other things make it viable.
Demo is only way to know - I already had the S1 Pre decision made a few years ago - it was not one I was going to make or wanted to make, but for an Active system with NAP500 amps it was silly-obvious to do and just affordable at that time.
But the sorts of improvements the ND555 2xsupply brings should still shine through the 552 Pre into a well set-up and installed system IMO. Many say it does - I think it will be musical tastes and room/bass handling that will make it more or less apparent.
Although more of the rewarding but less initially impressive changes were in mid and top-end for me - more mid-band openness and easy access to information presented without dynamic changes with what other strands of the music are doing - these sort of things are important to me. The treble is also smoother and more obviously extended in a way I like.
…but it kind of is in ‘you get what you pay for’ category, as the single supply ND555 shows very well its capabilities. If you pay attention to install and other ‘mania’ aspects then there is more to be had.
I have a 552 but found more or less exactly the same differences as DB reports. In addition I found a big jump in microdynamics and instrumental texture.
Sorry don,t get me wrong…i was demoing SL cables and decided to remind myself of the benefits of the second 555 ps. It was not a home demo. I had a home demo of SL cables, it did not work, i will now get a second 555ps. My point is its not a jaw dropping difference…but still very nice and beneficial.
I like the SL interconnects - once they run-in. They have a long run-in journey if you are wanting accurate harmonic linearity at low-level I found. They are very low noise compared to HiLine, but also that revealed a lot of run-in harshness that went very cold-metallic-harsh on and off for many months and gradually bottomed-out over nearly 9 months or more - I’d say it took mine a year or more to fully settle.
I accepted the journey as I’d heard a run-in set sound good - I do not understand how my Dealer managed to run-in their demo set far quicker than my set did - but mine ended-up beautifully open and lucid now.
The win is also significant with just a “mere” 552, microdynamics, tonal correctness, low end will arrive at the next level. Things which will pay back in spades within your musical preferences.
Nice review - aligns essentially with what I made of the differences and improvements.
Not for some immediately ‘in your face’ but actually very significant and worthwhile.
I’ve got to say I found the 2nd PS more immediately impactful than Collums. But then he likes Magicos, which I find a triumph of technology over music.