DSD64 for NDX...NDAC too???

Based on the below from Naim I would suggest not:

"We will be offering DSD64 compatibility to existing owners of the following products featuring the SHARC DSP: the ND5 XS, NDX and NDS network players and the SuperUniti all-in-one player.

How about NDX/NDAC  combo, can it play DSD64 ?

Yes - DSD is a data sampling process,  nothing to do with DAC.

So the SHARC DSP in the NDX process DSD then passes to NDAC assumed at that stage DoP?

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Not sure, but is DSD supported via SPDIF? I think not. You would probably need USB which the nDAC doen't have.

DSD in the NDX - thats the way it was explained to me

But I am still questioning the DAC issue (per pinkhamster):  Without a nDAC, the NDX still has its internal DAC, seems after the NDX front end it will take whatever that is.  Then what happens when you feed nDAC with a DSD file ???  hmm   ......   I guess it'll all become clear in time.

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I understood that upcoming sofware update will provide DSD64 compatibility to ND5, NDX, NDS and SU. In other terms it will enable DSD to PCM conversion of these players.

Using nDAC or DAC-V1 or any other external PCM DAC for that matter should in principle be possible.

Chag -

This is indeed the pathway.

In the end it depends if NDX can send the result of conversion from DSD to PCM via SPDIF-out or if it can only pass it on to the internal DAC.

DoP has got nothing to do with it as NDX converts DSD to PCM and there is no mention of encapsulating it into DoP for distribution to a DSD capable external DAC, which is not a logical thing to do for Naim anyhow.

Well SPDIF is a protocol that carries 2 or 4 channels of PCM data and therefore if the DSD is converted to PCM then I see no reason why it can't be sent via the SPDIF interface.

Simon

I don't follow this. All the Naim ND players oversample of up to 768k but this is simply a suitable integer multiple of the sample rate.. Such as carried in the SPDIF. How can it be a loss of resolution... This is a technique used to reduce artefacts in the reconstruction filter.

Simon

So a ndx will be able to take a DSD stream, convert it to PCM and send it to an nDac.

Or one could simply pass a PCM stream to an nDac?

I don't get it.

I thought the attraction of dsd was to have a dsd capable dac, usb out of a computer straight into dac. No?

Gary the DAC reading the DoP SPDIF stream will need to be DoP compatible, otherwise apparently all you hear is noise with faint music in the background.

Simon

Eloise - ok we only have fragements to work with but Andrew Everade's article says

"DSD64 can be played via UPnP, electrical digital or USB inputs, and DSD playback is kept as pure as possible by stripping out the digital header information, leaving only the audio to be optimised for the NAC-N 272’s DAC by integer resampling it to 40-bit/705.6kHz using Naim software, then feeding it to the 24-bit DAC...."

So the only way I know of getting DSD into the existing ND players via the electrical digital input is via DoP. DoP is used carry a DSD bit stream packaged up into a PCM sample container such that it can be carried in SPDIF etc.

Therefore if the ND player receives DoP, then it can clearly onward relay DoP out on its SPDIF output.

The SHARC DSP processor uses 40bit precision and therefore to convert the DSD in the DoP into a PCM sample word format used by the Naim DAC chips, a conversion need to take place as part of the reconstruction process. It would appear that the reconstructed 24 bit sample word data is oversampled in a similar way as for  PCM sample data is oversampled and filtered - prior to sending to the DAC chip.

Now as for DoP bandwidth - typically DSD64 of 44.1kHz sample rate can be carried in 176.4/24 DoP SPDIF stream. Therefore DSD64 can be relayed within the current SPDIF bandwidth of the ND players.

DSD128 of 44.1kHz sample rate is carried in a DoP of 352.8/24 or 384/24 SPDIF. Some DACs such as the Hugo support this via SPDIF, but as far as I am aware this is beyond the capability of the current ND player SPDIF interfaces. 

In summary we shall have to wait and see but -

1. The DoP can be reclocked and relayed without affecting the DSD sample data,

2. The Naim DSP processes the DSD data such that it can be processed by the current Naim 24 bit word DAC chips

Hi Simon...

i agree there here is no reason you couldn't pass the DoP encapsulated DSD to an external DAC (in fact you should be able to do that anyway with a Naim streamer if what is passed to the SPDIF is untouched a.k.a. bit perfect), that wasn't what I thought Gary was suggesting above - I read it he was suggesting the NAC-N 272 (and other devices once upgraded) would pass a convered PCM stream to an external DAC.  I may have understood his thinking.

eloise

Surely by this stage of processing and messing, you really just wanted either DSP room correction or tone controls?

Simon, re DSD output to external DACs, or compatibility with the Naim DAC...

my earlier post was in response to Chag/Aleg's musings about the ability to pass DSD64 2.8m/1bit post resampling to 705.6k/multi-bit, to an external DAC.  This doesn't fit with standard S/PDIF sample rates, and further down-sampling would arguably defeat the purpose of DSD encoding.

As you note, DoP encodes native DSD64 within a 176k/24 bit envelope which is compatible with SPDIF transport.  One might hope the DSD upgrade for ND* streamers would provide capability to output this as for PCM.

Naim positioned the DAC as an upgrade to the ND5/NDX streamers (as well as HDX/US), as an optimised up-sampling multi-bit converter. HDX/US are not capable of outputting 176.4 S/PDIF due to a clocking constraint.  I can't see any Naim business case around retrofit of DoP/DSD to the 'legacy' DAC flying - even if its architecture is technically capable, the effort in systems integration and testing would distract from other priorities, and where would be the financial return?

I think it will be very interesting to hear music via DSD through the ND* in comparison to PCM.  The PCM up-sampling filter coefficients represent one conscious design choice amongst many.  The act of bypassing the digital filter may give a different perspective on the underlying converter and analogue stages.

It seems we're entering a world, with PCM / DSD / MQA, where we'll be overwhelmed by choice...

Why would you want to convert DSD to PCM and output it as PCM to then send to another DAC.. you might as well reclock the DSD within the DoP SPDIF frame container and send it onto a DAC that can process, shape and reconstruct DSD. Many if not most modern quality DACs that support DSD do so including via DoP now. If you really needed to convert DSD to PCM I suspect you would be far better off doing that in software where you can optimize the variables to suit your circumstances... DSD to PCM conversion is not 'bit perfect'

Simon

Simon, adding to the confusion...in the past when you had theNDX/NDAC/555PS combo...did you try a XPSDR on the NDAC and NDX alone? With just the XP5XS on the NDX (no NDAC) is impressive. Assume the DSD translation would benefit as well. HCDR on the SN2 is pretty kickass. trying a plain 282/250.2 next.

Mackb3 I used to have a 555PS on my NDAC. I did try the 555PS on the NDX standalone.. I personally did not like the end result.. To my ears it was a little forced and unnatural.. Clearly there are differing views.

The DSD64 processing and clocking using the SHARC micro controller and processor ahead of the multi bit DAC chip will benefit from a highly stable clock. Improved power supplies can help achieve this, so yes the XPS2 might well improve things.. Only your ears will ultimately decide.

So no DR'd version tried on NDX. Thanks for the info and your experience. I will hold on to the NDAC and hopefully soon we can evaluate the DSD implementation via SPDIF.

Anyone else in this string tried a XPSDR on NDX?

M

I don't think that will be possible with the NDAC from what we have seen thus far

Simon