NDS - memory play?

Effectively yes. The music is served to the NDS as a data file. It just needs to be delivered faster into a buffer than it is used by the NDS, but no precise timing is required at this stage. It is only during the conversion to a bitstream and subsequent conversion to analogue that timing and therefore jitter is potentially an issue. All the conversion is done internally using precise clocks and the effects of jitter will be absolutely insignificant.

There is a display option on the NDS (and all Naim players I'm pretty sure) where you can see how full the buffer is.  The NDS like the other players stores some data in the buffer and plays out of it; if you unplug it from the network the buffer will empty and it'll stop playing.  But not instantaneously.

Thanks guys, thats good to know.

I was at a friend's place and we played a song into his dac with adaptive usb. The guitar imaging is blurrish. Then we tried a stello asynchronous usb to connect to the same dac and the guitar imaging is very solid and precise. It shows that the jitter with asynchronous usb is very low.

Then I went home and played the same song on my NDS. Surprisingly the guitar imaging is not as good as the stello asynchronous usb! It got me worried that NDS may be streaming from the network in real time and there is no memory play.

But I would still be curious as to why an NDS cannot sound as good as a mere Stello USB!

NDS sounds much more engaging than my friend's dac, but I'm just perplexed why NDS couldn't render the guitar imaging properly. Let me try using usb stick into NDS and I'll report back.

Just tried, imaging is the same between wired upnp and usb. Stello usb gives better imaging for that particular guitar passage (about 5 seconds). Is it by design? Because there cannot be much jitter if I use usb stick ...

You're comparing your system against your friends so different systems, different rooms. For a proper comparison compare the same source (stello, computer and music file) in your own system. 

Why do you think it's the NDS at fault ?  I don't really see how you can point the finger at this component as you are comparing your system to the one at your friends house hence my suggestion. 

James

About 5 seconds is it? Is that the only five seconds of music you will ever listen to? What does the NDS sound like playing everything else? Could be it's not for you, which is fair enough. But on a highly specific  five second evaluation? 

It's a highly specific 5 second guitar track. My friend uses a cary exciter dac which only has adaptive usb. We used a windows laptop running jriver. The imaging was very bad on that 5 second track - as in we could hear the guitar but could not 'see' the strings being plucked. We then plugged in a stello, and now the individual strings became very visible and precise. My friend was very impressed and purchased my one year old stello on the spot.

Came home and tried the same 5 second guitar track on the same flac file on the NDS via upnp. The imaging was sort of in between the two extremes. Left me scratching my head.

Of course on an overall basis NDS is much more engaging and musical than the cary with stello. I am not running NDS down in any way.

I assume that every other part of your systems are the same

Same interconnects

Same amplifiers

Same speaker cables

Same speakers

If this isn't the case then the comparison isn't valid.