Still a bit Lost

Brian - i've not had the nDac at home but have heard my NDX up against the nDac (with XPS). The nDac has a brighter more detailed presentation than the NDX which is somewhat darker. Both are very good so it's dependent on the rest of the system and how you wish to drive them on which you choose. 

I've also had the ADS/0 and Weiss DAC202 at various times in my system. The ADS is a very good, control software and general usability (firmware updates etc) is far in front of the Naim solutions. The NDX to me bettered the Linn ADS, in terms of musicality. I just felt while the Linn was a lovely player the NDX wanted to boogie whilst the Linn was a tad too polite. The ADS/1 though is supposedly a big improvement on the ADS/0. If you like the Linn sound then keep your eye out for a KDS Renew - basically the KDS/0 in a simpler box, part of an offer that Linn did for owners to upgrade to the KDS/1.

The Weiss DAC202 - very nice indeed but you need a Firewire connection to make the most of it. Its a first class source and decent headphone amp too. It betters the NDX - more open and detailed but doesn't have the NDX flexibility. Given the direction my system has gone, i'm wondering whether to keep the NDX and add an XPS/2 or go back to the Weiss DAC202 myself. 

James

In my humble opinion the Naim DAC is the best of the digital products you list. It is the only I feel will offer SQ equal to or better than your CDX2. The Naim DAC gives a truly holistic rendition of the music. The NDX would be my second choice and has the added advantage of being a streamer; I just preferred the Naim DAC. I have no idea what a non-Naim PSU would do it, but the 555PS is superb with both these items.  

The only stand alone DAC I've heard that rivals the Naim DAC/555PS is the BAD Alpha. I have not heard the very expensive dCS kit, but could easily believe they are quite superb, but too dear for me. I prefer to the Naim DAC/555PS over the CDX2/555PS. 

The best digital source I have heard is the NDS/555PS and that is the way I think I shall go provided a couple of minor points get iron out (I want to be able to update the firmware without any need to go out and buy a Windows computer; I'm hoping Naim will make it friendly enough so you can update without any need to use a computer though if I can use a Mac or Linux device then I can cope). For what it is worth, the NDS threatens to be the last streamer/DAC I would ever buy, as whilst it may be possible to make something better, I'm unconvinced I'd ever need such a device. 

As always opinions will vary and I believe the ADS has been improved substantially since I heard one demo'd. I was not overwhelmed by the one I compared with a CD5i. I have never heard a KDS. 

However, there is no substitute for listening yourself.

The Weiss is far more versatile, and sounds better than the Naim dac, I believe the new 202's come with an async 24/192 async USB input as well as FireWire.

H.

It doesn't sound better to me, but there is no substitute for auditioning and choosing the one that suits you best. 

I find it impossible to choose for somebody else - I guess all we can do is say which we would buy given the choice - I'd go for Naim DAC followed by NDX and others may choose differently. However, the NDS remains the benchmark for me. The Chord DACs sound very good too, but if Naim didn't make a DAC then I'd probably buy a BAD Alpha (though it is two box if you want a USB interface, so that the USB is isolated from its more sensitive parts). 

Interestingly a friend bought around his BAD ,( Berkeley Audio Design ) dac and we were able to compare that to the Naim and Weiss 202, again the Weiss was  superior in every area, resolution ,tone dynamics, the Naim dac sounded at its best when connected via the Weiss, ( using the Weiss as just a FireWire interface).

H

I think all I'm doing is emphasising the importance of an audition, as only the person who will listen to his or her system can really decide what they like best - for me there is a clear preference from those listed by the OP - though I think I could live happily with the NDX/555PS (if I had not heard the NDS). 

We often have these X vs Y threads, but ... all we can ever do is say we prefer X to Y or vice versa. We may prefer different sonic presentations. 

If the OP was hoping for a definitive answer then this is unlikely to happen.

All the best, Guy