Ok Peter, thank you for the answer! I was trying to find out if Mac would be a viable solution with your DAC.  It seems that it is not.
I'll have to try a PC-based solution with XXHE and see how it works in my setup. So, I'll take a look at the recommended platform for XXHE and start from there.

Paul, thanks for your quick answer!

Now, a little more details about my system and my preferences:
I listen mostly symphonic music and opera, but I am listening jazz and blues sometimes.
I am using an EmmLabs CDSD SE (latest version, with metallic transport) and EmmLabs DCC2 SE directly into the power amp - BAT VK-600SE. The IC is Audioquest Wild. Speakers: Raidho/Eben X-4 . Speaker cable: AQ Everest. Power cables: AQ NRG-5. Power conditioning: Isotek Sigmas .
I was trying to built a pc-based playback system that would get near the EmmLabs combo, with no luck.
2-3 years ago I have built a PC with the CMP2 specs, into the tiniest details (hardware and software), and I was very disappointed with the results. I tried XX Highend in the early stages , but it was quite unstable at the moment, so I sticked to foobar + ASIO. I have used several interfaces (ESI Julia, Edirol UA-1ex, M-Audio Transit, HiFace, Modded HiFace) and several tweaked computers (most of them highly tweaked and configured to play from memory). None of them could hold a faint candle to the Emm transport.
Until I switched to a MacBook Pro and ART Legato. First I tried Amarra, didn't liked it, then sticked with Audirvana for a couple of weeks, until I installed Pure Music. This is the first setup that I find acceptable compared to the CDSD se.
I find amusing that some of my friends say that my system sounds more hi-rez when playing just redbook CDs than any other system they heard, using hi-rez material.
The thing is that I find the differences between redbook and SACD (same album) minimal, and I think that the recording and mastering are far more important.
I believe that detail is important, but only when it comes with timbral and tonal accuracy and integrity, coherence, macro-dynamics and layering.
I believe that upsampling in software is good only for NOS DACs, and detrimental for DACs that have DSP.

Just my 2c, sorry for the long post!

All that being said, I will try a PC based solution, with W7/64 and latest XXHE . And I am very curious about the USB NOS1!

Hi Peter, have you tried PureMusic for playback?
I prefer it by a large margin in my system to Amarra and Audirvana.
At the moment I prefer the "NOS" setting, probably due to the USB bridge I am using - ART Legato - limited to 44.1k .
It is available as a trial download, usable for 15 days: http://www.channld.com/pure-music4.html .

Regards,
Bogdan.