To clarify, did you install the driver in your computer and connect the computer's USB port to the USB input in the NAD? May I ask how you verified that your computer was not internally downsampling the 192kHz to 96kHz?
Thank you!
I installed the T + A USB 2 driver software several weeks ago and used Foobar to play FLAC files to my T + A DAC 8. Unfortunately I did not look in the Foobar configuration to see which output driver / software the being used. Last night did the NAD USB driver software install, connected the D3020 and immediately ran Foobar.
I picked a 24/192 FLAC file, and it sounded great. This morning when I got up, I found that Foobar had locked up trying to play the JPEG of the cover art. So I restarted Foobar and to my great surprise I got the error message window sample rate not supported. After 20 minutes of fooling around I final changed the output module selection to DS - USB Audio, and Foobar would play the 24/192 file with no problem
I have also been wondering if Direct Sound could be down sampling the WAV file to 96 KHz. Looking at the function set of Direct Sound it does not seem that sample rate conversion is one of them.
http://msdn.microsoft.com/en-us/library/ee418868(v=vs.85).aspxAt the output end of Kmix the GFI filter might be cahnging the sample rate
http://msdn.microsoft.com/en-us/library/windows/hardware/ff537047(v=vs.85).aspxAlso what I don't know is does the T + A driver software use Direct Sound.
This evening I set up my system again, but now the output module name has changed from [DS- USB Audio] to [DS - NAD USB Audio]. The NAD Output module which I think I was running this morning seems to have disappeared. Instead there is a output module labelled [ASIO: NAD USB Audio ASIO Driver] but it does not work giving the error message "Unrecoverable playback error: Could not initialize the driver". I did quite a bit of fooling around this lunch time ad that seems to have changed the driver installations.
The D3020 is supposed to accept 24/192 Khz on the Coax SPDIF input, so the DAC has the capabilty. Any decent modern USB receiver chip should be able to accept USB 2 data rates, so then it just a matter of the USB driver.
The much more expensive D7050 has the same sample rate limitation and the same driver as the D3020, which I also find surprising. May be NAD were not happy with the consistency of 24/192 playback, so they have disabled it for the present time ?
I am very much an amatuer on this stuff, appreciate your insights