Good news. The problem was in monitoring program AIDA64. When I'm closing AIDA64, the player works without any problems  It's strange, but true.

You lucky. But mine not works. In win xp works fine. Have to wait win 8 final release. I could to use virtual machine, but it's ridiculous and not convenient. 

Got problem with connecting the player to pc via usb-cable in Windows 7 (in WinXP all ok). The problem is WPD FileSystem Volume Driver. Here is description of the problem. I couldn't to do anything, because the player disconnects faster, than I have time to do something. How to resolve this...

And there are many models of zero on ebay: OPA2604, OPA627, OPA627U, 2604U. What deferents between them? And what the best?

I'am very interesting in Zero DAC, because very good price. But not sure, if that DAC is will be good for my headphones. I have Beyerdynamic DT770 PRO/80 (80 om). And Creative X-Fi Titanium PCIe (SB0880) as sound source. Was anybody test Zero with DT770 80 om? Any noise, enough power? Or need...