500 users question

Has anybody tried 2xPS with the 500?


Thanks James.

I am listening and undecided, but am hearing a lot to like. Have it for a few weeks - the acid test will be moving back to just one (as it was with the 2nd PS on the 555). But right now I am having enough fun to leave it in situā€¦ this system grooves!!! :blush:


Hi Robbo so are you using to Nap500 power suppliesā€¦by just simply plugging in one supply for each sideā€¦and nothing else. I read somwhere that there were earthing issuesā€¦

I may be wrong but I thought @RichardDane said Naim felt that two ps didnā€™t really work.

Initially it can sound really good - in a very "hifi-ishā€™ kind of way. However, after a while you then realise thereā€™s something not quite right. See here;

This is where I think Naim could do some researchā€¦I am sure it could be developed I am also equally sure that you are correct its not just a question of slapping anther supply on. What would be good about this approach is that it would fit in with Naimā€™s modular ethosā€¦and possibly give a closer stepping stone to the Statement. I suspect the grounding in a shared chassis is
an issueā€¦maybe an earth link between the 2 psuā€™s could helpā€¦development, development, development - come on Naim. I know the 500 is a niche product, conversely there must be quite a few 500ā€™s out thereā€¦and such an upgrade would be tempting to most 500 ownersā€¦

It would mean developing the individual power supplies for purpose as mono units. I recall Roy mentioning that he felt that there were likely ā€œparasitic artefactsā€ from the unused side of each power supply.

Interesting makes senseā€¦maybe you could keep the same basic psu design which is excellent but combine the outputs with a mini internal link bus bar arrangementā€¦basically allowing the psu to act as one huge power supplyā€¦all future 500ā€™s could have this as standard. Existing owners maybe could exchange there 500 psu (which could be updated in the future) and get 2 new psuā€™s ā€¦ for say 12-14k ā€¦ just a thoughtā€¦


Thatā€™s what I thoughtā€¦how many 500ā€™s have been sold over the last 22 yearsā€¦I am sure a good percentage of owners would be interested ā€¦ not only that it would refresh this fabulous amplifierā€¦giving excellent publicity.

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Sound like a great idea. However, something tells me it may not be quite so simpleā€¦

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It never is!!! this is the genius of Naims patient and fastidious development ā€¦linking it up would probably generate huge hum ā€¦although in theory the psu would be nice and balancedā€¦come on Naim dust of the 500 and give it some develeopmentā€¦

When my brother worked at Heybrook helping design and build there amplifiersā€¦they took the P100 and gave it twin supplies totally separating - separate transformers and separate rectification and capacitors. My brother said the same HiFi impact was great but something was missingā€¦ there was no parasitic redundancy in their implementation - strange, however if memory serves me well they kept the single board and cut the tracks to separate the power railsā€¦ I will ask him about how it was configured and tested.

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So why no such problems when you add a second 555ps to the nd555 or cd555, as surely its very much the same?
The 500 is mono design and split into left and right and i would have thought the power supply is basically 2 x the same in one box

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Thats what by brother thought when he separated the P100 amps to accept twin suppliesā€¦it worked but sonically something was not quite rightā€¦ Obviously with the 500 you have huge redundancy as one psu supply is left unused if you use the psu unmodified. That can leave the transformer a bit imbalancedā€¦I suppose. I think doing surgery to the psu may be possible to link it together to form one mighty power supplyā€¦should be fairly straight forwardā€¦

Not being an R&D engineer I have no idea, but I would hazard a guess it may be down to the two sections of the 555PS being for different things - analogue and digital perhaps? Or perhaps something that just affects a power amp?

Like you Richard not a clue really, i just know that the 500ps looks like it has a few windings from the transformer that feeds 12 big caps, that all look the same onto one board that also looks like its 6 x the same. That to me says that it split 3 to the left and 3 to the right.
So running 2 x power supplies and each only then using half the internals, if that gives you extra reserves as far as the transformer is concerned i dont know as like i said it looks to have a few windings on it, so i guess it wouldnā€™t as part now wouldnā€™t be doing anything?

Inside the 500ps.
As you can see its like what i said i think?