Naim NAC 552 into Chord M Scaler/BluMKII?

Hello all, and I hope everyone on the forum is well.

I have a bit of a puzzling problem if you will. I am looking to experiment by adding a NAC 552 into my primary headphone listing rig, but I am unsure of a few things.

The current setup is a very good system, and consists of:

Naim ND555 w/ 2x 555DR power supplies
Chord Music BNC to Chord BluMKII
Dual Wave BNC cables to Chord Dave
Chord Music XLR cables to Viva Egoista 845 headphone amp
Viva is running dual Takatsuki 274B tubes and dual WE845 Linlai tubes

My question is, would adding the NAC 552 into this chain improve the sound any?

My second, more important question is, how would I connect the 552 to the BlueMKII. The Blu uses the same inputs as the hugo mscaler. I don’t see a way to convert the DIN outs from the 552 to the BNC input on the Blu. I can use a cable that has DIN to XLR, but that would mean bypassing the Blu/mscaler entirely.

I have done many searches on this, and ultimately led me to post after not seeing away to do this.

Ideally, I would like the signal path to be:

ND555 > NAC552 > BluMKII > Dave > Viva

Is this possible?

If anyone is curious why I have a 552 just laying around, it was used in a 2 channel setup I had about a year ago.

That’s not going to work as you are using the ND555 as a digital transport to feed the Blu upscaler and then using the DAC in the DAVE to provide an analogue output to the Viva.
You would need to go

ND555 > BluMKII > DAVE > NAC552 > Viva

With the NAC552 sitting between DAVE and Viva.

I’m not really sure what the 552 would really bring to this setup though. You’ve already got a headphone amp with a volume control so are making the most of the fixed line outputs from DAVE.

Out of interest, if you’re just using the ND555 as a transport, why do you use dual 555PS supplies, or is this a hangover from a previous setup (as you have a 552 laying around…) ?

Indeed, as James said you would need to follow his flow, but the 552 will in the grand scheme of things be detracting and filtering the sound… so if you like the filtering effect of the 552 then you can try, but it won’t be improving the audio.
For best audio performance use the DAVE headphone amp, or take the output of the DAVE into the headphone amp directly.

The exception may be if you want to take the DAVE output and split into speakers and headphone… here you could take the tape out of the 552 and feed into headphone amp… with the DAVE going into a 552 input. You would turn the volume to zero on the 552 when only using the headphones and not the speakers.

As others have said a pointless thing to do, and will certainly change the way it sounds. But you might like what the 552 will inject into the mix? But i certainly wouldn’t do it.
The other question is why have a nd555 especially with 2 power supplies as you aren’t even using the dac just the streaming section i take it, if so this is a very strange way to do it, very expensive and once again a total waste as you might as well just use a much cheaper streamer.


Its a hang over from the previuos setup. It was already hooked up so I left it that way.

As to the 555/Dave, since I am using the digital out (BNC), isn’t that using the Dac in the 555?

The reason I want to use the 552 is so that I can use the analog outs on the 555, go through the 552, and use the dac in the Dave instead of the 555.

No it’s not using the dac. Dac stands for digital to analogue converter.
Your dave is just a dac and that is doing the conversion, as in digital in.
You are only using the streaming board in the nd555, so you have one power supply powered up and doing nothing as the twin supplies split the analogue and digital side and then only use part off each power supply in each 555ps.
You could get very much the same results using just a streamer into the dave.
If you use the nd555 analogue outs into say a 552 then you would lose the dave, or have 2 different digital sets ups.


A good dealer can save money🥺

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You are using the Dave at the moment. You could sell the ND555 and the two power supplies, buy an NDX2 and get pretty much the same sound as you get now, and have a lot more money in the bank.


Simple answer, NO it won’t improve the sound.

Personally I would go to Nd555 as transport into Nd555 with 2X 555 dr as dac into Mutec Reference clock , with 3 X PhoenixNet in cascade mode with 3 X Shunyata Sigma lan cables and Taiko server.
A simple and cost effective way to maximise sound quality.
A 552 of course and Dave/ Mscaler/ Sean Jacobs ps for headphones listening.

So I guess I do not understand the “Digital out” and “Analog out” of Naim streamers. I have the ND555 and also a NDX2 in a different room. So does the digital out use the internal DAC or not?

I thought that the Digital out used the internal DAC, and the analog out only used the streamer output and was for using an external DAC.

No it’s the other way around. On the ND555, the analogue output is post the internal DAC and what you would connect to the input of the your Preamp.

The ND555 digital out is the S/PDIF digital output (effectively before the ND555 internal DAC) that could be fed to an external DAC, or in your case, the Blu MkII upscaler, ahead of the DAVE (which is the DAC).

Here is a diagram from the ND555 White paper - you can see the S/PDIF digital output comes from the Digital board, ahead of the DAC / Filter boards and analogue outputs (right hand side).



Ok thank you. So based on this since I am using the digital out to the Blu/Dave, I suppose I do not need both 555PS power supplies? Which one would I disconnect (see picture)? Output one or two? I can use the unused 555PS on my NDX2 in my 2 channel setup.

***Edit, I think I may know the answer. The CD555PS single unit can power both the inputs off one unit. The upside to having 2 is that each power supply is only powering one input each. Is that accurate?

Yes, that’s right. A single 555PS will power the ND555 using both Burndy cables. As you say, using two 555PS power supplies dedicates a single 555PS to the analogue section and a single 555PS to the digital section of the ND555.

As you’re using the digital output of the ND555 to feed the upscaler, you’re not really getting the benefit of using two power supplies and so moving one to power your NDX2 is a good idea.

To connect the NDX2 to the 555PS, you’ll need an 11 pin S-XPS Burndy cable connected to output 1 on the 555PS.

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Why not just use the NDX2 in the headphone system, as i am sure it will sound the same as the ND555 how you are using it. Then put the ND555 and both power supplies in your 2 channel set up.
As both units share the same streaming board after all, and that’s all you are using in the headphone set up.
I guess you use the NDX2 into a pre in the other system? So swapping would give you a much better dac/source into that system.

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Dunc, here is the system chain. Yes, I am using a pre in the other system. I went tube pre for that setup as I have started to really lean into the tube sound. I have a 552 “laying around” but its not being used in any system right now.

  1. Audioquest Niagra 5000 > ND555 (dual CD555PS) > BluMKII/Dave (with SJ psu) > Viva Ego 845

  2. Audioquest Niagra 1200 > NDX2 > mScaler/TT2 > Woo Audio WA33 (as tube pre) > Dynaudio Contour 30

All connection cables (ps, interconnects, etc) are very high quality so no worries there, don’t think I need to list those. I have other systems, but these would be the two affected.

I know everyone keeps talking about the 2 channel setup, but I listen to headphones more often than speakers due to work. I also think that a quality headphone setup can match a 2 channel. Any ZMF on the Viva is just incredible.

Thank you James. I see what you mean. Since I am only using the digital section of the ND555, it makes no difference to use 2x psu.

As only one part of the single psu is being used anyway (digital), correct?

The digital out uses the streamer DSP chip. The analogue output uses the DAC chip(s) which in turn are fed by the DSP. The DSP is set to either be digital or analogue mode, the streamer can’t do both at the same time. Point of note the DAC board is used in digital out mode (but not the DAC chips). This is for the clock.
The streaming transport board and the DAC board (clock) feeds the DSP.

I see you also use a chord dac in your second system as well.
So once again not using the naim dac and just using the streaming board in the NDX2.

Well obviously you prefer the chord dac’s over the naim, so if i was you i would sell the naim gear and recoup as much money back from these items as you can.
It looks like you have a ND555, 2 x 555cdps, 552, and a NDX2. Selling this lot will certainly bring you in around ÂŁ35000 depending on age, service, etc. (UK prices)
But certainly you will be able to get 2 very good streamers for that, or even one that could feed both systems.
But right now how you are using the naim gear is a complete waste, and as said already you could get the same results with 2 much cheaper streamers feeding your chord dac’s.