dCS and the NAP 350 mono-block - A match made in ...?

Hi guys,

I have a question regarding the potential of the new NAP 350 mono-block. I see that new classics are now accepting balanced XLR. I must admit I don’t know much about this kind of XLR + Naim’s old XLR differences.

My situation now is this. I have my third NAC 552 DR replacement after having:

  1. Indicator light protrude - 552 replaced (wait 6 months) - See 552 indicator light can come out?
  2. Woofer scary popping as seen here - Naim hissing - YouTube

My new 552 replacement just came last week and it still exhibiting the same woofer popping problem. My dealer is at a lost for word, but he did not say anything and just said go straight to Naim for RMA. Another 3 months of wait I supposed.

I am now looking at moving to dCS side (maybe).

Thus the question is, if I get dCS Rossini/Vivaldi (both Apex), and in the event I upgrade my 250DR to the new 350 mono-block, is the connection just simply a simple balanced XLR connection?

And is such exercise a really silly thing to do? Seeing that I already have 500-series front-end (Pre+Source).

To add a bit of a context.

When the dealer loan me their shop’s 552, the rest of my system do not exhibit the woofer popping phenomenon. This is the part dealer and I are very puzzling.

When dealer took my 552 to their shop and switch on, also no issues.

But now I have 2 brand new unit of 552 making my woofer dance in a way that make me feel uncomfortable. I am truly at a lost for word.

If you plan on using a dcs dac into the new Nap 350’s, them yes as i understand all you need is normal balanced xlr interconnects.

That is what I figured also. I also heard Naim do this to have better compatibility with 3rd party equipment. So perhaps the new amp is no longer seriously needed a Naim pre-amp to front it so religiously?

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That explains it, doesn’t it? The error is somewhere else in your system.


I don’t know, but the fact that they are now using a more universal type of connection may well be to appeal to non naim equipment users.

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Problem is when they loan me their 552 and it sit in my house and I use it for months (while waiting for my new unit to arrive), everything is fine. And I use it for TV and music daily. So can’t explain that my other system are problem.

You mean that the one you borrowed from your dealer works at your home and that your own works at your dealer but not at your home?

Yes correct. When the dealer loan me their 552, everything is fine.

When my dealer bought my unit to their shop and test, they did not detect any issues.

I have to mention. This popping thing does not appear immediately. So I not sure if the dealer stress test it days in or out or they just switch it on and play music for a brief moment.

Last week when my new unit came in, I can happily played it for 3 hours. Then I let it rest and go back to work, when suddenly my living room give a loud popping sound. That is when I am shock the new unit give similar issues.

Okay, then I understand. Very strange, but judging by your description, the error should still be in some other part of your system. The chance that two different 552s, one of which is brand new, will have the same fault is probably equal to zero. Have you tried replacing any other part of the system to see if that makes a difference?

It could be some kind of RFI? In extreme cases the Burndy cables can sometimes act like aerials. However, this is a phenomenon mostly experienced outside the UK and Europe. North America and Singapore/Malaysia are where some of the worst cases have occurred, from my own memory. In both areas I experienced RFI that was so high it prevented a CD555 from operating (!). The Singapore one could be cured through very careful Burndy dressing - pulling them wide apart IIRC - but the one that occurred in Canada could only be cured by moving into a different room.


I am from Singapore and the Burndy cable is the one we did not replaced. I will show this to my dealer. Tks Richard for your additional knowledge.


Replacing the Burndy cable may not fix the issue if it is RFI, but I guess it’s always worth a go.

Have you tried a different source from your ND555 through the 552?

Unfortunately I only got 1 streaming source.

Does the RFI mostly act in concert together with a faulty Burndy cable?

Because the dealer loaner unit does not have such issues with the same cable and power supply.

RF is a tricky one to pin down. It can sometimes only arise with a certain combination of things all within a particular tolerance. I would suggest your dealer try to make direct contact with the Naim factory here as there are one or two members of the R&D team who have experience with these situations.

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Want to ask. This so-called RF if happen can make a woofer in and out in such a manner and will it quickly spoiled my speaker in any unsafe way. Do I need to somehow stop immediately using it.

This might also explain why my dealer shop did not have this issues if it is location sensitive.

I don’t know, sorry. It’s probably not brilliant for the speakers, and certainly annoying.

Not at all. Appreciate the insight you bring to his matter. Will discuss with my dealer.

Looking at the video he posted in the first comment I would say it’s definitely not RFI.

As the new 350 mono amps are not out yet, then obviously, no one will know if the pair work well together.
But i did try my vivaldi apex dac into my 500dr directly using the rca out from the dac. The inpovement i got was fantastic by removing the 552dr pre. I guess the new 350 amps will work fine, and maybe even better than the 500dr, especially when you have balanced connections. I take it the new amp are true balanced though out?
I guess when the new 350 comes out you could try them and compare to other amps to see if you like the pair together, as i found i liked what a true class A amp did when paired to my vivaldi.
Also go vivaldi if you can stretch to it, the rossini is fantastic, but the vivaldi is simply something else, very special indeed, and you can certainly hear why it’s one off the best dac’s you can buy