I don't have the NOS1 DAC but rather just a DIY USB 16 bit NOS DAC. I have tried every player I can find. XXHighEnd sounds the best by far. I have been using it everyday for 3+ years and yes it keeps getting better. Sure it is ugly (sorry Peter), the UI sucks, the demo version needs to be restarted every 1/2 hour or less, getting it set up for the best sound quality is not obvious.
Every now and then I take the time to try all the new and old players thinking someone has matched XXHighEnd's sound quality by now, but no.
If you are fussy and using your computer as your music source you owe it to yourself to give it a try. Perhaps with your gear you will not hear a difference. But from my experience if you are using a USB DAC, the generic Windows USB driver and your DAC is not half bad then you will hear the difference. I can't comment on internal sound cards or motherboard audio because I don't use them anymore. If you try it please report back what gear you have and if you can hear a difference.
I will give you a few tips to get you over the hump.... You need Windows7. The demo version sounds as good as the paid/registered version, it is same download/program. I have to confess I have never used the registered version but I know the player well enough to be able to say the sound is the same (in all but the most extreme situations, NOS1 DAC). You do need the latest version.
http://www.phasure.com/index.php?board=1.0 The demo/unregistered version can be setup to restart by pressing Alt-X on your keyboard when it times out after 20 minutes or so. The demo timeout seems somewhat random, sometimes 10 minutes, sometimes 1/2 an hour. When it timesout playing a song in the playlist it restarts that song from the beginning but doesn't lose its place in the playlist. Obviously that doesn't bother me enough to buy the player or stop using it. I just do ALT-X and it keeps going. It takes a bit of work to set that up but the player supports/instructions support that feature.
XXHighEnd has 4 different "sound engines" or methods for sending the music to your DAC. Engine #4 sounds the best. The other engines are still there for backwards compatibility with older version of windows and comparison. Engine #3 appeared when VISTA was the current version of Windows and only recently has engine #4 appeared and been perfected. Oh Yeah!
Engine #3 had a tendency run into problems at times and produce a tick tick tick sound in the music because the timing of filling the buffer could get out of sync. Engine #4 doesn't have this problem and it sounds even better, double win! Even with Engine #3 problems I stuck with it for years because nothing could match its sound quality.
I expected XXHighEnd to sound the same using any Windows 7 computer that could run it, but that isn't the case. I found powerful computers sound better than less powerful computers. A dual or quad core 2 GHz machine will sound better than a dual core 1 GHz netbook or tablet. I didn't expect that but after 8+ hours over two days and testing 3 computers and reading comments at the XXHighEnd.com website that is usually the case. If you have a 2 Ghz or faster computer try engine4 KS-Mode=Standard buffer=2 q1=0 ThredPrio=Realtime, if you are using a less powerful machine try engine4 KS-Mode=Normal buffer=32 q1=16 ThredPrio=Realtime. This isn't Foobar, you have to invest some time tweaking the settings and use your ears.
If you don't hear any difference between Engine3 and Engine4 or other players then be happy and enjoy the music. Sometimes I wish I wasn't so hard to please
