Playback DSD File format on NDX5S 4.3

Exactly what I thought ChrisSU. So the sum of all the parts are not singing off the same hymn sheet. I will give the USB a go. Your a star and Many Thanks for a prompt response.

Steve

You can run MinimServer for OS X on your Mac, and it will serve the .dsf files.

If I read this correctly, this means that if I have an NDX running the latest 4.3 firmware upgrade and it is being served files by a UnitiServe (in server mode not playback mode) then it still can't playback DSD files?  If that is the case then excuse me for using this term but that is an EPIC FAIL... 

Best way to think about it is that the UnitiServe is a PCM-only server - it has no DSD-capable playback hardware as regards the PCI audio card used to generate an SPDIF output. The only sensible option (as I see it, not speaking for Naim here) would be to offer:

• UPnP Content Directory service of .DSF and .DFF files, using whatever tags make sense for the largest majority of down stores, and
• DSD-to-PCM conversion, for use on internal hardware (permanently enabled) and selectable for UPnP services

Of course - this would only make sense if these features could drive new business - but here's the rub: this would not make sense in the context of Uniti-family products (which lack an internal SHARC DSP* and therefore DSD playback), except as a means of enabling playback of DSD-capable files over Ethernet.

* - SuperUniti does have an internal SHARC DSP, NAC-N 172 XS does not (similar to Uniti products)

Thanks David, so if I understand you correctly, even though I am just using my UnitiServe as a server via ethernet I can't play DSD software (even though my NDX is DSD compatible)?  What if I have an UnitiServe-SSD and am storing the DSD files on an external NAS and using the UnitiServe to serve the DSD files to an NDX? 

If we pull this apart a little . . . might it be technically easier to support serving dsd files, even if their playback to spdif output cannot be supported??

I was thinking, in a totally non-technical way, that just the serving function aught to be essentially a "pass-through" - just pass along the data. But I have no idea really!

Again - not speaking for Naim, but the servers ought to be able to play through the local outputs anything that is within their content index.

To that end, there is presently no means (official or otherwise) of using an asynchronous USB output from the servers to feed a DSD-capable DAC. DSD-over-PCM would require additional data encoding to feed the resulting output data at a sample rate that is not natively supported for internal playback (176.4 kHz), which might present an interesting problem....

You would like think this should be the case Bart but it would appear that the UnitiServe can't even do that at the moment (Phil Harris confirmed this to me on another thread) and my guess is that it is unlikely to ever be able to.  Sorry Naim, but this sucks big time!

It (obviously) can't at the moment -- but really my question was regarding the nature / extent of the modifications that'd be needed to support the serving of .dsf files. 

We can all guess . . . you 'n me both.  

And for me, this has certainly not yet reached the "sucks big time" stage yet as there is relatively little native DSD music (that I would be interested in purchasing) available at this time.  I certainly do not intend to re-purchase my substantial redbook and higher-res pcm library in DSD - especially DSD created by converting pcm.  Barely a tempest in a teapot to me presently.

We agree about the availability of DSD material so from that point of view it is not a big issue, at least at this stage, but what it does seem to indicate is that the UnitiServe is not much more than a CD ripper with limited serving potential that may become even more restrictive over time.

For reasons best known to Naim, 176.4 kHz sample data rate is not supported by any of the servers. This is a shame, since if using the DoP to carry the DSD64 sample data, a 176.4kHz PCM framing data rate is required. So although no re sample encoding of the data is required to provide DSD via DoP, the underlying, probably hardware limitation, of not being able to provide a 176.4kHz PCM equivalent sample data rate appears to prevent any of the Naim servers providing DSD64 via DoP currently.

Simon

Thanks Simon.  It's a pity that effectively an NDX can be made DSD compatible but if you are using a UnitiServe to serve files to the NDX things fall apart and your only option is USB sticks BUT if I had a simple NAS MinimServer type set up I would have no problems.  Surely Naim must be able to see the irony in this state of affairs.

It started as ONLY a cd ripper / tagger / server / player.  Then Naim were able to offer substantially more -- the ability to load downloaded files onto it and serve those too.  That was a rather major addition of functionality that was not present when I purchased it.  So in my experience, over time, capabilities have been ADDED.  None lost.

As technology moves forward there is a risk that any piece of hardware will not be able to keep up.  That was a major thought as I bought into my first serving solution (the uServe) and Dac (the Naim Dac).  "Is this the right time to buy?" is always a question.  I am comfortable with the decisions I've made and the great music I continue to hear.  Others are, obviously, less so.

Absolutely you can play all of your DSD files from a nas.  You probably own one already as you are backing up your uServe to one.

If I could add my findings so far:

1. The UnitiServe plays no part in hosting or playing a DSD file. I added the .dsf extension to the files that it should look for in the US download folder and on scanning found no such file. So if you want to play a DSD file look elsewhere to store it.

2. Sticking it on a USB stick and using the front port on my ND5 works.

3. Using Minimserve works a treat on my mac and finds the folder I placed the file in using the iPad app. Only downside is my mac has to be up and running to find the folder.

In my opinion, its not a problem yet as there is hardly any software, but the non-seamless integration of their hardware, seems to me a bit pants! Feels like Naim have only done half the job!

Thanks for the update. This is how I see things too 

It's a problem that is not limited to Naim - it's exceedingly difficult to design an output codec that supports high-res output at 176.4 kHz as well as 192 kHz without possessing the ability to switch between two clock crystals (once you consider the requirements for division of a single crystal-referenced clock frequency to support both bit clocks) or without using a PLL-based arrangement (oversimplifying this a bit) to generate the reference clocks, with a corresponding drop in quality (increased jitter).

To the original point, DoP-compatible streams at 176.4 kHz could be generated for consumption over the network (or over asynchronous USB, in an ideal world) but would be unplayable locally, which largely defeats the purpose of the servers as standalone (local output) players.

David, i don't follow in as far as i see the synchronisation using fixed crystal controlled frequencies to output a SPDIF of both  174.6 or 192 not really anymore demanding than say synchronising between 44.1 and 48 for example - and of course 174.6 can be frequency quadrupled from 44.1

I suspect the limitation has historically been because 174.6 has been a relatively rare sync rate compared to 192 and so various hardware designs have ommitted this rate. Evidently with DoP 174.6  becoming more common,  I would expect to see more support of this rate  going forward.

It wouldn't be the first time that specific file types were limited to specific outputs (for e.g. Toslink on a Naim Streamer doesn't support 24/192) so why should this be any different?  

Not having it also largely defeats the purpose of having an all naim network audio system (for e.g. an UnitiiServe + NDX) where the UnitiServe serves (after all that is what it is called not a UnitiPlay) DSD files to an NDX which can then play them.

56.448 MHz crystals used as a a single shared-master clock source tend to exhibit fairly high (by audio standards, anyway) clock jitter, which is no big deal in a modem but not very welcome in a high-performance audio playback device. If one adds divide-down / multiply-up networks into the equation, the risks ultimately outweigh the benefits IMHO.

24.576 MHz crystals are far more common, and can be sourced more economically, though they forgo the capability of providing a high-enough multiplier to drive an oversampling DAC at hi-res multiples of 44.1 kHz.

David, but, if this is so,  we are talking transport framing jitter here, which for most modern designs is decoupled from audio sample jitter as used in many modern DACs. (Although cross talk noise will in the real effect couple between the two clocks)

I am also not aware in the Naim DAC design for example with respect to audio sample performance, that the jitter rates vary for sample frequencies

You are aware that TOSLink transceivers themselves aren't rated to 24/192? You can run them at 24/192 (and we do drive them at 24/192 with a 24/192 source file) but they're not guaranteed to be reliable.

The UnitiServe has always been a CD Ripper and server and it still is and it still does support the same filetypes that it did 'yesterday' - it has not somehow been crippled overnight or have functionality removed - and as such still fully justifies its role within any audio system (not just a Naim one - we have many customers using UnitiServes and NS's as servers within LINN systems).

It does not have DSD support at this time but - as always - I cannot tell you what we may or may not be working on with regard to future developments and releases on any of our products until such time as an official release of information is made by our PR / Marketing guys.

Phil

Thanks Phil, Yes I am aware that Toslink isn't rated 24/192 and that is the reason it is only 24/96 on the Naim streamers instead of 24/192 like SPDIF etc - that is exactly my point.  If the UnitiServe player isn't rated 'DSD compatible' but the Serve was able to serve DSD files then I see now reason why the functionality shouldn't be employed where it can.

I also never said the UnitiServe had been crippled overnight.  I am a relatively new UnitiServe owner and user and in the short time I have been using it I have discovered a a couple of functions that I believe it could do better, this just happens to be one of them.  Another one that I would really like to see is the ability to order albums within artist folders by release date.  I have previously asked the question asked about this but got no response.  I still like my UnitiServe and appreciate what it can do, but simultaneously pointing out where it could be improved.  If Naim want to listen cool, if they don't that is their choice.  

I'll leave it there.