DSD

2L offers tracks in a range of formats to compare. 

The NDS is only able to play the 2.8mhz rate, aka DSD64. 

Bear in mind that although the Burr Brown Ti chips  Naim use support DSD, this feature is not used. DSD is achieved by transcoding on the fly to PCM so the DAC always sees that.

This makes sense too. The DSP in the streamers is tuned for the idiosyncrasies of the DAC and the analogue output stage. And you cannot do DSP on DSD (in any practical sense) so feeding DSD directly to the DAC would bypass a lot of the effort Naim put into making the streamers sound how they do. DSD support is more for convenience in this case. 

Whether the DSD to PCM conversion results in the same, better, or worse PCM stream than a commercial PCM hi-res download is open to debate.

tonycurran1 posted:

Hi i am going to try a DSD download can any member recamend  a good one to try

It depends on your preferred music genre.   DSD for me is best heard with the less complex & processed recording methods,  in other words not rock pop or full orchestra,   look for folk, jazz, acoustic, coral & live recordings.     Even better if recorded in one or other of the DX fomates or native DSD.   HighResAudio have a good selection,  Sound Liaison are DSD specialist with Jazz,  Blue Coast are the DSD leading pioneers with folk & classical but have crazy prices,   HDTracks are starting to get a few,  2L as mentioned above,    look around th web & pick on,  you can’t go wrong,  I always choose DSD if there is a choice. 

FZ, the DSP in the streamers is not optimised for any ideosyncharcies in the TI chips, but rather instead the AD processor. The DSP comprises of a standard zero sample oversampling converter followed by a Butterworth low pass filter with extra poles added. This filter is however implemented as an IIR as opposed to FIR... although this adds phasing errors compared to an FIR implementation, Naim felt with their implemtation of the Analog Devices DSP SHARC processor technology this was the lesser of two evils as it produced less power related processing artefacts compared to encoding the digital filter as an FIR using the Analog Devices processor. This approach has been followed with the new streamers too.

The Naim specific DAC ‘tuning’ is achieved in the analogue stages after the DAC with the precision i2v converter and the analogue electronics Sallen-Key lowpass filter.

Simon

I have a couple DSD albums - High Res Audio

really like Allan Parsons on DSD but mainly classical & jazz in DSD format