NDS/555 vs. NDS/2x555

I heard the effect of a 2nd 555ps when I had my factory visit at Naim. What I heard as the effect was even further natural tones, less noise floor..... Simply said more real. I heard it through a statement amplification, so it might have been more clear than in a 500 system, but it was clear at that point in time that once I would make that step. So far I had other upgrade priorities but one I would have upgraded my 500 to DR this one would be next in line when funds would become available.

While I still had a difficulty to get my head around having 2 powersupplies to provide a source with juice....

I am interested in how you are experiencing it...

Hi Graham,

About 18 months ago my dealer was visiting to try and identify a problem with my system.  In order to do this he had with him a set of duplicate components so that we could swap them out one at a time to see where the problem lay.

After discovering it was a dodgy Burndy, I commented on the fact we had a second 555PS and wouldn't it be 'interesting to hear what it does?'  My dealer had not heard an NDS with two 555s either so we hooked it up and sat down to listen.

From the first track to the last, I found it utterly captivating; drums sounded more realistic than previously, there was a huge reduction in the noise floor, the music seemed to flow with a greater sense of ease and transparency and the whole sound became much bigger.

The only downside was the subsequent dent in my wallet and the difficulty in trying to configure my two Fraim stacks to ensure ideal cable dressing when I made the purchase!

As Bert says, it will be interesting to hear your thoughts.

Cheers,

Ian

My experience was slightly different, in the end I decided that the at the time new Super Lumina IC & SC was a better upgrade than a second 555DR which while an improvement as mentioned already for me wasn't striking enough, or enough to buy, so stuck with single 555DR.

I heard one vs two in a friends system. I took my well burned in 555dr to his so we could dem the two. With one 555 I found the sound to have a real connection musically, I really felt engaged with the music. We added the second supply and I found it sounded very impressive, much more hifi but to me less engaging and less together and less harmonious.

Dan43 posted:

My experience was slightly different, in the end I decided that the at the time new Super Lumina IC & SC was a better upgrade than a second 555DR which while an improvement as mentioned already for me wasn't striking enough, or enough to buy, so stuck with single 555DR.

I understand your remark. It's not a jaw dropping type of improvement, but a more refined upgrade. So people might not like it enough to spend that kind of money, for me however it was clearly one thing to do, but it is also clearly the last one on my upgrade list.

I have a 2008 555 player with the original Power Supply upgraded to DR status in September 2014, along with the same upgrade to my 552.

Both upgrades were well worthwhile with all the expected improvements and more.

I thought long and hard about adding a second PS to the 555 not least the outlay involved. A converted PS has slightly different software from a new one and as the analogue and digital are now powered individually, so I am told, there is a "right" and a "wrong" way to connect them to the head unit. The second supply was installed late summer 2015.

From switch on there was no way I would revert to one PS. The player is totally transformed so much so it becomes a different and considerably better and more musical player to my ears. Its just brilliant making me want to keep on playing AND buying more CDs.

No wonder Naim use two Power Supplies with the NDS.

douglas

I have DR & non DR 555PS with NDS. The difference is not a day & night but it is very fundamental. For sure Super Lumina change is easier to notice. I have tried to take one 555 away but no way to do it. Sound comes more natural, analogue, blacker background, drums/voice improved separation with 2x555. So it is much more musical instead of hifi. I really like it & believe me I tried to live with one only.

Hi Graham,

technically you'd be using the 2nd 555PS to supply just two power rails (+/- 22V). Given naim's enthusiasm for multiple rails (e.g. Supercap) and the fact that the NDS' 2nd Burndy can actually accommodate 6 rails, I had speculated earlier (search '556 PS for NDS?') that naim might wish to do a 556 PS with 6 rails. Or you could get one built and go beyond the standard 2x 555 setup 

Cheers,

Stefan

I agree Super Lumina is probably a more fundamental improvement than adding the second PS; however, 18 months ago when I bought the second PS for my NDS, Super Lumina wasn't available.

I have auditioned a full SL loom and found it to be an exhilarating experience.  I suspect the two 555s on the NDS really showcase what the NDS/SL combination is capable of.  Super Lumina will have to wait while I save up for it but in the meantime I feel a very real emotional connection to the music and don't regret going for the second PS.

Cheers,

Ian

My view on the second 555PS is known so I won't detail it here - but it is entirely positive, but only if the mains sequencing is gotten right. You need to plug the 'Digital 555PS' near the 'Analogue 555PS' lead and 'upstream' (farther from the wall socket) from the Analongue 555PS and Pre Amp plugs, in that order.

If this is overlooked or ignored you will get mixed results: the timing will be poor, there will be 'something wrong' with the HF and the bass will be too much and out of proportion. I think/know the two supplies connect their Ov reference at the DAC chips inside the NDS head unit and there is a loop through the two supplies to the mains which means you must not interpose any mains noise between the two plugs as it will get into the loop and you hear it.
This is what I found - a big improvement if plugged-in correctly, but otherwise it sounded wrong and the single supply may be preferred even.

I've demonstrated this effect to another dual 555PS owner in his own system and he could hear it clearly and preferred the same configuration as me, once we tried a few permutations.

If you approach this with the idea that mains plug-in sequencing don't matter, or should not matter then you will probably fail to have success with two 555PS. When I tried it on 555 Head unit and NDS Head unit at home the NDS was less sensitive than the 555 CD head unit, but it was clear what was better in both cases.

DB.

I have SL as well but feeling that it is more like creaming the cake, instead second 555PS makes it one more layer & nicely wet. In my case the music flow changes as well or due other changes feeling so, this creates real engagement. No matter how much SL improves the sound but second 555 is changing the whole presentation IMHO.

The second 555PS - if configured properly at the mains end:

Fills-out the low-bass definition and provides power where before it seemed to roll-off, if in a nice way.
Lowers the noise floor throughout top to bottom, but for me most usefully in the voice band.
Removed an edge from the high frequencies and made them sound more natural.
Provided a more seamless and confident presentation. The single supply by comparison sounded like it was not as steady on complex-mixes and when heavy bass lines appeared you lost clarity - a 'breathing' effect I do not like, so that disappearing was good!

The two supplies do different things than the SL loom does , but they nicely compliment each other. For most people I'd advise the SL loom upgrade first, followed by the 2x555PS - but for some the other way around if their music contains more heavy-mixed rock.

DB.

this is my story of the 2nd 555PS on my NDS. 

I started off with 2x555PSs, but at some point, convinced myself that this was ridiculous overkill, and sold it. The funds generated helped with other domestic issues.

Over the next few months later, i felt NDS performance was somewhat less convincing and found myself playing vinyl much more often than before. 

To cut the long story short, i bought a 555PS, again -- and when it was all settled -- things just 'felt' better for me.

But, could i tell the difference in an A/B test?? Probably not. I would have to 'live' with either setup for a while to determinewhat i preferred, and in my case, it seemed i preffered 2 PSs. I wish that wasnt the case as the money could be used elsewhere right now ... but sadly this isnt the case and my 2nd 555PS is staying...

just my 2c worth...

enjoy

ken

When I upgraded my NDS's 555PS to DR status, the improvement was significant. I went from "no complaints" to "just right for my ears", and so I stopped there.

Of course I continue to be tempted by upgrades: a second 555PS DR, an SC (to replace my 552's AUX2) for my SuperLine and, of course, the rest of the SL cables (beyond my NDS's DIN5 interconnect).

Have resisted so far for two reasons: 1) I really do like the way everything sounds right now, and 2) retirement on a fixed income is only a few years away. As a result, I am more carefully weighing each major spend versus additional savings and investments.

But I continue to very interested in other owners's thoughts on this topic, and am looking forward to reading what Graham thinks!

ATB.

Hook

Wow, lots of replies.  Thank you everyone who took the time to post something.  Apologies for delay in my reply, did a 130 mile round trip yesterday to cook a nice Christmas meal for my elderly parents.

Given the accepted wisdom of "source first" my upgrades this year have been in an odd order.  Changed the preamp, then a full loom of SL cables then bought DRed NAP300s, all before looking at the Melco and second 555PS.  Now with hindsight I still believe that was the right order as the pre, cables and 300DRs all made a bigger sonic improvement than either the Melco or second 555 seem to have.

To be honest I'm a tiny bit disappointed by the Melco.  Yes, it does make a difference.  As someone else said it appears to clean up the music.  But £6K is a lot for what it does.  It's better but am not sure it is value for money in my eyes.  However that's a relative thing that everyone has to decide upon individually.

With the Melco still in use I then added the second 555.  Again to my ears it does improve some areas.  It feels like it's squeezing out the final bit of detail that the NDS can resolve and the presentation of some of the intstruments seem different but that is a very subtle change.

Unfortunately what I'm also hearing is a top end that's a little too bright.  The S1 and SL cables deliver more HF yet in a very delicate way.  The second 555PS makes it sound splashy.  It sounds a bit "hifi" and almost as if the system is trying too hard and not creating a convincing sound.  The way it currently sounds the downsides outweigh the benefits.

So today I might have a play with plug ordering.  What I currently have is (from left to right) : 1x switched wall socket connected to standard ring mains then 2x unswitched wall sockets connected to dedicated spur.  Into the left hand socket of dedicated spur is an 8 way mains block.  Right hand socket has S1 pre connected to it directly.  The switched (standard mains) wall socket currently feeds the digital input of the NDAC.  All cables (inc one to Melco) are Powerlines.

On the 8 way mains block the ordering is (from left to right, right hand end is closest to mains cable connecting it to wall):

(1) Melco (2) Snaxo Supercap (3) NDAC XPSDR (4) 555PS (5) 555PS (6) 300DR (bottom most bass driver) (7) 300DR (top most bass driver) (8) 300DR (BMR)

I'm going to have a listen with the NDAC powered off and disconnected from the standard supply in case this is causing an RF loop as mentioned elsewhere.

Gary - any recommendation on plug ordering?  Which of the NDS feeds is the digital input and which the analogue?  At present (when looking from the back of NDS) 555 #4 is connected to right hand Burndy input and 555 #5 is connected to left hand.

Of course just to make things more exciting, the XPS DR connected to the NDAC has a habit of blowing fuses and I only have one spare, so if possible not powering that off reduces the risk of the running out of fuses...

Graham,

Im surprised with the level of kit you have that you are using an 8 way mains block. I find these deteriorate the sound. Is it not possible for you to have a dedicated consumer unit with one 10mm circuit for each piece of equipment? This would probably give you a bigger lift to the sound than the second 555 and melco combined at a tiny fraction of the price.

I found upgrading the mains to be the biggest upgrade I ever made.

The advice from Naim has always been (at least it was when I asked them) that a single radial is better than multiple radials. It's something to do with the earthing. Multiple sockets attached to a single radial might be a way to go. 

Reading these threads makes be happier than ever that my system has only two mains plugs, which is one of the reasons I chose what I have. 

I totally believe that the plugging order makes a difference, but it does seem an extreme length to have to go to, particularly where plug order can seemingly determine whether the addition of a 555PS is a positive or a negative. 

Graham, with regard to 8 plug mains block, effectively acting as a 13 amp spur, I find these can really improve things when the mains cable feeding the block is braided with many smaller conductors to impede RF .. It really quietens the mains and helps spaces in the audio and allows the sound to breath better without the fuss or possible side effects of conditioners.. I find it reduces the visible hash on the mains ( when using a scope).. compared to dedicated rings or radials on thier own. Do you use such cable? If not it might be worthwhile looking out for it if not.

Simon

The mains block is from MCRU.  No switch or power light and the internal rails are silver plated.  The mains lead from it is a heavy duty 6mm cable which is screened.  Cost about £220 and was a big step up from the elderly Chord Company blocks I was previously using.  The ring main cable is also from MCRU and is 10mm sq, screened cable at about £20/m.  Installing the dedicated spur made a massive difference to SQ and to be honest I'm dubious that this is the weak link given how the system typically sounds.

I'd need 10 unswitched wall sockets which would be an eyesore and I doubt would pass the WAF test.  Maybe I could squeeze a bit more from it in this way but not convinced that is the solution to my current situation.  I know the 1 vs 2 argument is fairly divisive but want to give it every (realistic) opportunity before handing it back and making a decision.

Simon-in-Suffolk posted:

Graham, with regard to 8 plug mains block, effectively acting as a 13 amp spur, I find these can really improve things when the mains cable feeding the block is braided with many smaller conductors to impede RF .. It really quietens the mains and helps spaces in the audio and allows the sound to breath better without the fuss or possible side effects of conditioners.. I find it reduces the visible hash on the mains ( when using a scope).. compared to dedicated rings or radials on thier own. Do you use such cable? If not it might be worthwhile looking out for it if not.

Simon

I think Russ Andrews' mains blocks (and power cables) uses a braided weave to reduce RF.

Mike 

Hungryhalibut posted:

The advice from Naim has always been (at least it was when I asked them) that a single radial is better than multiple radials. It's something to do with the earthing. Multiple sockets attached to a single radial might be a way to go. 

Reading these threads makes be happier than ever that my system has only two mains plugs, which is one of the reasons I chose what I have. 

I totally believe that the plugging order makes a difference, but it does seem an extreme length to have to go to, particularly where plug order can seemingly determine whether the addition of a 555PS is a positive or a negative. 

Yes, there's definitely benefits to be had when running a low box count system and this is clearly one of them.  I don't mind the extra complexity and potential sensitivity of an active system because to me, that's a minor trade off compared to the SQ you get. 

If you don't want to pfaff about with this and don't want a system that dominates the room it is installed in then I can easily understand why you went in the direction you did.

I've been running 2x555ps on my NDS for some time now.  One is DR which sounds best on the digital side.  The NDS really comes to life with two power supplies... there's more magic, more sparkle to the sound.  

Streaming audio is very tweaky.  I've found linear power supplies for all parts of the chain are crucial (NAS&UnitiServe) as well as high-end ethernet cables.  I use a mix of Sarum and Chord C-Stream.  

MDS posted:

Simon-in-Suffolk posted:

Graham, with regard to 8 plug mains block, effectively acting as a 13 amp spur, I find these can really improve things when the mains cable feeding the block is braided with many smaller conductors to impede RF .. It really quietens the mains and helps spaces in the audio and allows the sound to breath better without the fuss or possible side effects of conditioners.. I find it reduces the visible hash on the mains ( when using a scope).. compared to dedicated rings or radials on thier own. Do you use such cable? If not it might be worthwhile looking out for it if not.

Simon

I think Russ Andrews' mains blocks (and power cables) uses a braided weave to reduce RF.

Mike 

I struggle a bit with many Russ Andrews' products because their marketing makes them appear a bit "snake oil" to me.  My only experience is with their consumer unit so my perception may be grossly unfair, I don't know. 

We can't post links here however if you Google for "mcru 10mm sq shielded mains spur cable" you'll find the ring main cable I'm using.  It also uses a braided weave, as you can see in the photograph.  The cable from the 3 pin plug to the mains block is the 6mm sq variant of the same.

Graham Clarke posted:

...

On the 8 way mains block the ordering is (from left to right, right hand end is closest to mains cable connecting it to wall):

(1) Melco (2) Snaxo Supercap (3) NDAC XPSDR (4) 555PS (5) 555PS (6) 300DR (bottom most bass driver) (7) 300DR (top most bass driver) (8) 300DR (BMR)

I'm going to have a listen with the NDAC powered off and disconnected from the standard supply in case this is causing an RF loop as mentioned elsewhere.

Gary - any recommendation on plug ordering?  Which of the NDS feeds is the digital input and which the analogue?  At present (when looking from the back of NDS) 555 #4 is connected to right hand Burndy input and 555 #5 is connected to left hand.

Ordering from wall and away from it should be:

Bass Power Amp(s) - Mid/HF Power Amps - Snaxo PS - Pre - Source Analogue PS --- Source Digital PS

Probably consider the Melco as a 'Source Digital PS' in this case and put it at the very end.

The idea is that the Power Amps draw the most dynamic current and the Bass Amps the most - these need to have access to the wall first and not be daisy-chained through all the other supplies, as the otherwise introduce large music-related IR-drops onto the other supplies. The Power Amps are not Class A units so they are worst offenders. You also need them sequenced to keep all loops between mains and equipment small and non-overlapping.

As for the NDS supplies - the one which turns on the display is the digital supply - it will also be the one that the light goes out quickest when you turn-off the mains, as the digital side of the NDS draws most current - the Analogue PS will linger longer before going off.

Try this - it should resolve all your problems, as I've verified it in multiple systems.

DB.

To Graham's OP:

Big difference across the board. Texture and timing seem to benefit the most, with spatial positioning also resolving. Lots of straight HiFi differences too like tracks resolving into multiple tracks, harmonies resolving better into different voices, subtle strains and whips emerging from the floor, bass that starts and stops with a bit more precision. And all that. 

Above all it's just more musical enjoyment. Unforced, natural, more immersive. Like an NDS/555PS only better. It is not a diminishing return in my view but since it is so easy to do the AB we can each of us draw our own conclusions and make our own value judgement.

Overall I'd say it's definitely the equivalent of a box upgrade!