555ps x 2 or 555ps dr x 1?

I have a single 555ps non dr on my CD555.

I am considering a 2nd 555ps non dr on the CD555.

Also considering a 555ps dr on the Cd555.

Has anyone compared 2x 555ps non dr against 1 x 555ps dr? On either CD555 or NDS?

You should DR your 555ps ASAP before Naim stops that service forever. You can always borrow a second 555PS DR to try. It is a worthy upgrade but it may not be your first priority. I moved from a CDS2 to a CD555 and added a second PS555DR and then DR’ed the first one. I use the 2xPS555DR now on an ND555. I dearly miss the CD555!

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I was under the impression that Naim had officially stopped the dr upgrade?


that was going to be my question too, oh how good it would be if they brought th eDR upgrades back.

The DR upgrades are postponed due to supply chain issues. Once the demand for new goes down/supply improves/less covid illness I understand they will start to offer again. How long this is though…

You can mix DR and non DR power supplies. Would be best to try both the DR on Analogue and Digital to see which you prefer. There is a difference and the preference is not always universal.

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As a long term user of the CD555 I had my Power Supply DRd soon after this option became available. About 3/4 years ago I had my friendly dealer hook up a second one: this time brand new. From the off it was not going back. Some have reservations about using two PSs but not me.
Perhaps a bit academic at this moment, but a re-built PS is to the same spec as new.
As I understand it the second supply separates digital and analogue giving the player an easier time.
The biggest complement is its gives me as much pleasure as my Stiletto plinth LP12.

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I was under the impression it was not a good idea to mix dr and non dr power supplies…?

So that’s interesting….

Suppose its all a question as to how for do you go. I think you can mix DR and non DR. Better if they are both DR I suspect.
Of course its another big black box. My wife uses the phrase: “climbing up the walls”.
She has a point.

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I will probably buy a 555ps dr and get my non dr 555ps serviced and dr’ed when Naim decide they are able to restart the process…

Hi Wenger, yes I have compared the outcomes. Even at the time adding a second non DR 555PS provided a big uplift in replay. It was simply ‘more of everything’ :hugs:
When the time came to get the dual PSs DR’ed and serviced I decided to do one at a time to avoid being without music. As the 1st DR version returned and even also trying to it singular you got the the positives of DRing, but some of the grandiose of dual PSs was missing. When I had the second one back and full house was re established, if my audio memory serves me correct at the time I didn’t actually feel the DRing of the one used for the digital supply brought anything much from a DRing aspect.
In other words if you are running 2 PSs I think sticking the DR version on the analogue side will suffice. Enjoy the CD555 it’s a wicked machine! Best Peter

I was wanting to hear from someone that has done the comparison….that is extremely helpful….

The CD555 is a magnificent beast…I am certainly looking to hearing it with a second 555ps

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My understanding from previous threads earlier in the year is that Naim have stopped offering the DR upgrades from non-DR and there is no intention to bring them back. DR units can of course still be purchased as new items.

I use a mix of DR 555PS and non-DR 555PS with my CD555. The non-DR one is best used to drive the digital circuits, with the DR one dedicated to analogue. There was a very significant sonic upgrade going from one to two supplies - worth the bucks and no going back.

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Maybe someone from Naim can provide clarification on the dr situation?

If I did buy a 555ps dr……my only concern is not being able to have my non dr 555ps d’red.

If you put the non-DR one on the CD555’s digital circuit, you should be fine. There seems to be limited, if any, benefit of powering that circuit from a DR unit.


As I and Dynaudio1 said :wink: Sometimes just a service does wonders also. Before I got my S1 I had had both my 555PSs serviced 7 1/2 years in just for piece of mind. Best Peter

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I assume having a service is still possible?

My gear was serviced before Covid ( feels like decades :roll_eyes:). I don’t really know, so maybe give your dealer a call. Should you have any doubts you shall be most welcome to come here for a listen should you wish. I’m in west Sussex and only an email through RirchardD away :+1:t3: Best Peter

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Thanks for your kind offer.

I am down in Somerset but if by any chance I am heading your way sometime soon I will be in touch.

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Am I missing something obvious…

On the back of the CD555 their are 2 inputs….which one is digital and which one is analogue?

Wenger, the analogue is the right one of the 2 seen from above, or left input socket if you look from the back of the mighty CD555 head. Enjoy Peter

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