552 > 52 - a retrograde step or not?

Morning all,

Not sure what to do and where to go with my system and would very much appreciate some thoughts from others who might have done similar.

I have a 552/500/NBL system, which I’ve had for quite some years now. The sources are a KDS/3 and an LP12/Aro/geddon/akiva into a prefix/supercap.

The amps are older (non-DR) versions and are coming up to the stage in which they will need to be serviced. I have however noticed that whole system just does not seem to engage in the ways it once did. It’s had its annual strip down and rebuild, which helped as ever, but it still isn’t quite somehow doing the business in the way it once did.

My mind was turned therefore back to the most enjoyable system I had, which both gave a huge wow factor getting it and throughout the time I had it always kept me thinking “one more song” in a way that I just don’t seem to be feeling at the moment. This was a CDS2/52/52PS into 135s and SBLs. After that,I upgraded through a 252 and a 300 to the current setup. All seemed like improvements at the time, but now I’m not sure…

I haven’t heard a great deal of DR stuff, but the very limited opportunities I’ve had to hear it have in truth left me a bit underwhelmed. I appreciate I am in no position to offer a firm view on its qualities on such brief acquaintance, but initial impressions were that the sound signature was more akin to other, third-party power supplies I have also heard in the past - better hi-fi, less groove. I am therefore a bit reluctant to incur the fairly hefty costs of upgrading it to DR and/or servicing when I probably wouldn’t get this back on the sale if I decided that it still wasn’t doing the business.

I did wonder about an ND 555, but have seen several comments to the effect that it is in fact voiced very similarly to a KDS. Certainly, my experience of owning various iterations of the KDS have been that it’s sound has been more “naim-like” with every generation.

Has anyone felt similar and sorted out the problem by going back to something like a serviced 52/135? Equally, if anyone has any other suggestions, I’d be very grateful!

I appreciate that at this level many solutions will need a listen, but where I live is quite remote and getting to hear the sort of thing which might assist is quite a hassle, so I would appreciate any guidance beforehand.

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This is in no way a comprehensive answer but we too sometimes experience the symptom of gradually being less and less inclined to listen to music on the main system. We can’t work out why but get on with other aspects of our lives. Then one day, I check to see when the cd head unit (sacrilege, I know), power amps or a power supply (supercap, XPS, 555PS) were last serviced and the penny drops. Off for a service goes the overdue unit.

Conventional wisdom and folklore say service intervals of 8-10 years for non-500 series and 15 years for 500 series. This doesn’t work for us. Our NAP135s lose their mojo after 6-7 years and the 555PS lost its oomph after about 10 years. All mojos and oomphs returns after servicing though.

Post service, all the life, vitality and musical engagement comes back until the next time.

So I would start with a service and DR of the NAP500. That’s a biggie, a real upgrade and a half for everyone that I know has had it done.

Hope this helps, if only a bit. BF

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I presume you have had your 552/500 from new, if so, they must have given you many years of enjoyment. But the sound does drop off as they near their servicing point. I would start at looking to either service or DR and service . Even if you decide to sell on you will need to factor in lack of servicing in the resell price, or service and sell on? You may be pleasantly surprised and decide to keep?


I progressed up the Naim ladder to 552DR/500, all recently serviced/upgraded by Naim, driving my DBLs. Source was LP12/Radikal/Urika/Ekos SE/XV-1t with a KDS/3 for streaming.

Frankly - and particularly after the 552 DR upgrade - I was underwhelmed listening to my favourite rock/fusion/blues music. The rendering was super detailed with amazing separation of the instruments … but it just felt like the musicians were all playing separately in the room and the excitement, boogie and ‘togetherness’ of music played on my previous 52/135s was gone.

I reverted to 52/135s and had them serviced and the sound I loved came straight back, affording me many joyous hours of listening, ever since the ‘upgrade’ to 52/125s :grinning:

Subsequently I switched the Urika phono stage to Superline (with Supercap DR) and this has improved things yet further, to the stage where vinyl is sublime, as is the KDS/3 but in a different way.

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I have a preloved 552/500 bought recently but serviced 3 years ago. Adding PowerLines has been the icing on the cake for me. If you haven’t already got PLs then borrow some from your dealer. It’s then a matter of service with or without DR. The 552/500 is a marvellous bit of kit as I am sure you know.

What I have come to realise is that when music is less engaging it’s the subtle harmonic structure that is missing. The 552/500 is good at this, but the whole system and it’s environment needs to be finely tuned. One can then turn the volume down as well.


Remember, you don’t need to go down the DR route. You could just elect to have the kit serviced. You’ll save a whole chunk of money and it will be back to sounding as good as it did when new.


Is the 552 getting a signal earth connection to ground?

the KDS/3 does not to my limited knowledge have such a connection.

The 552 pre-amp should therefore have signal earth to ground connection.

Talk to Naim and your dealer on how to achieve this.

If still it doesn’t sing, then as Richard Dane said, time for a service, if the cost of a DR upgrade does not work out.

As for DR kit, I am very aware and sensitive about my kit having the signature Naim rthymic qualities, and the DR kit has it. No doubts at all to my ears.

In fact I regularly listen to a Non DR 500 series kit at my friends place, and then compare to other DR kit at my own and other friends who own full Naim DR preamps and amps, there is no loss of PRAT at all, the DR kit betters the older one in all respects.

I traded a 555PS non DR for a DR version. The DR just has a more refined effect without losing any dynamism.

Hi oscpercy,

I find my system can become less enjoyable when I am under certain types of pressure or stress as the music rather than acting as a diversion allows certain demons to play more readily on my mind, then I find work a more effective diversion.

Assuming this isn’t the case then I think you have excellent sources, and if you have made no changes then a service looks like the natural route.

WRT changes:
Have you added and widgets or items recently? I find one thing that can alter the sound signature of my system is what I call grounding. Having bought a 300DR a couple of weeks ago and replugged in my EAR868pl I tried my LP12/Aro/Geddon and found it sharp. The solution was to disconnect the Aro grounding cable from the EAR earthing pin.

I route my ground through ONE route. That is items that have no direct earth the mains cable get connected through the EAR868pl if that is in circuit. If I am using my Townhend Allegri then I route them through my Klimax DS.

In terms of plugging in other bits of equipment I find my Oppo 105D has an interesting influence. Through the Allegri is injects noise and degrades SQ if left plugged into the pre when not in use.

Just some thoughts. Good luck,


To add to what has already been alluded to, you have a world class pre amp and amp which you initially enjoyed. It’s seems that the problem and solution is obvious. Service them and if you can, get them both DRd in 2 steps if absolutely necessary. I wouldn’t move away from a 552/500 combo.

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Oscpercy, the good thing here is that you used to enjoy your system in its current configuration ie a mental reference point. The 552/500 combo is in so many ways unbeatable, so have it all serviced ( also possibly DRed) and see what you find after say 3 months of run in. As for the idea of reverting back to the 52 Pre allow me to quote an old Danish humorist, who once said : Just imagine that these dyer times will once become ‘ the good old days’ ! ATB Peter
This is by no means a dig at Bluesfan :stuck_out_tongue_winking_eye:


Mortally wounded Peter, mortally. I shall have to put the arm chair back in the spot that offends you most now!

(only kidding)

Best regards, BF


Peak Naim, end of


The problem is, is that it can be many things that start you feeling like that.
The way you feel and your own hearing i think is the main one.
Then your system going off.
May be a disconnect and reconnect of all the cables would be a good start, then if you still feel that its not right, then may be a service is required.
I had until recently an olive system that consisted of a 52 (one of the last ones made) 3 x 250’s and active S600 speakers, it sounded great and i was very happy until i started trying the 500 series.
I would say that going back to a 52 and 135’s, would be just that, a backwards move.
The only way i would do that is to release some money out the system if i need it.

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Hi Ospercy, could anything have changed with your mains supply or any new, possibly disruptive, items been plugged in either in your premises or nearby?I’ve had some mains issues which are still ‘in process’ with U.K. Power Networks scheduled to install a new, heavier gauge LV cable. You would likely be surprised at how much your voltage supply can swing around and the left field factors which can influence that. If your system can still sound good to you occasionally and is not always disappointing then perhaps worth a thought. First stage would be to to get a meter to measure the voltage from the sockets you are using to feed the system. These can be bought cheaply enough.
Having said that, if the equipment is nearing a service interval, I would agree this is most likely cause.

It’s difficult to know where to start. All sorts of things could be at play, some of them inexpensive to fix or even free. Since you break down the rack and rebuild it every year, my first thought would be to revisit this. Maybe do it all over again.

Have the speakers been moved? Is there anything that might have degraded the quality of the mains supply? Has any furniture in the room been replaced, changed position or reupholstered? Once the option of spending money to solve it looms into view, my next move would be to get it serviced.

You’ve got a top flight, world class system. It sounded good enough to move up the ladder through a number of best in class systems. If it’s no longer doing its magic it can be restored. You should not need Power Lines, DR upgrades and SL cable upgrades to make it sound like it did when it first moved you so much. Just a routine service.

DR, Power Lines and SL cables have transformed my system to levels of musical communication that I never though possible. But this was moving up from what I considered to already be a fantastically good base line. I hope you can get back to your amps’ base line. I’m inclined to think you can.

I don’t know if you could recover your service costs if you end up selling your 552/500 but they are certainly going to be worth more if serviced.


Thanks so much all, very much appreciated…

I have had a look around and although information is a bit limited, I think I would probably get most of the cost of a service back even if it did not do the trick and I did look to something else. Plus, as has rightly been said, I did enjoy the amps very much for a long time (indeed still do) - so hopefully no reason why that should not be the case again. Particularly given that time has as so often, rather slipped away and the 552 and 500 are now 15! I had not realised quite how old (and presumably in need of a service) they were.

Will report back, but in the meantime, thanks again to all


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