I think I may, with the help of Keith at Purite Audio and Marco at M2Tech, have resolved the issues with the Hiface and JRiver Media Center 15. The comments below are based on my own use of the products in my system which comprises:
Acer Laptop (Windows 7 x64) (JRiver Media Center 15: Full Version)
Samsung 1.5 TB USB External Hard Drive
M2Tech Hiface
Naim Audio DAC / Naim XPS Power Supply
Naim NAC52 Pre-Amplifier / Naim Audio Supercap Power Supply / Naim Audio NAP250 Power Amplifier
Naim SBL Speakers
Marco sent me the beta driver (1.03.140) and I installed it having previously removed the driver available from the M2Tech website (1.03.141). It didn't appear to make any difference. I was still getting error messages when I tried to play 24-Bit/96kHz FLAC files and 24-Bit/192kHz FLAC files.
I then started to work my way through the dCS Guide to Computer Audio and made sure that my installation of Windows 7 was correctly configured. I changed quite a few things in the Windows audio configuration! The setup procedure for Windows 7 can be found on Pages 26-28 of the guide. Having completed this, I reinstalled the 1.03.140 driver that Marco supplied and configured JRiver Media Center 15 to work in WASAPI mode. This process is described in Pages 34-37 on the guide.
16-Bit/44.1kHz FLAC files and 24-Bit/44.1kHz FLAC files would now play with the 'Open device for exclusive access' box checked (I had not managed to get sound output with this box checked before). I thought that everyone was OK until I tried playing 24-Bit/96kHz FLAC files and 24-Bit/192kHz FLAC files. The sound was breaking up badly. I managed to resolve this issue by returning to the DSP Studio settings and changing the Prebuffering setting from its default value of 6 seconds to 2 seconds.
Everything now seems to be working well. The only problem I have experienced is changing from one 24-Bit/192kHz album rip to another without first stopping playback. This could however, be due to the fact that I have a USB rather than a NAS drive.
If you need Marco's beta driver or the dCS Guide to Computer Audio, I have posted them in my Hotfile account. Links are as follows:
http://hotfile.com/dl/56760438/e9363ab/dCS_Guide_to_Computer_Audio.pdf.htmlhttp://hotfile.com/dl/56760085/99006ff/win7vista103.zip.htmlI hope this works for you if you are experiencing difficulties. I have to say that the sound of JRiver Media Center 15 in WASAPI mode is superb. To my ears, it is preferable to Foobar2000. In JRiver, the WASAPI mode sounds less 'hot' than ASIO and more detailed than kernel streaming. I also much prefer the GUI of JRiver Media Center to Foobar2000/DarkOne 2.1, but that is down to personal taste.
Finally ... Thanks to Keith at Purite Audio and Marco at M2Tech. They have both been so helpful in working with me to resolve the difficulties.