In his excellent review of the excellent Benchmark DAC2 HGC, Erick Lichte says he wasn't quite convinced that he had managed to get bit-transparent playback with JRiver Media Center 18 under Windows. I have Media Center - albeit version 19 - and a DAC2 and I'm pretty confident I have bit-transparent playback.
JRiver makes it very easy.
In Tools > Options > Audio set the Audio Device to either Benchmark DAC2 WASAPI or Benchmark DAC2 ASIO driver if you use Benchmarks customer driver. In both cases make sure the Volume mode shows Disabled volume. Make sure all the DSP settings are off, and you haven't selected any sample rate changes. If you use the ASIO driver, click device settings and select the "Device uses only most significant 24 bits" and select "DSD bitstream in DoP format" to get DSD streaming. At the Windows level you need to select "Allow applications to take exclusive control of this device", "Disable all enhancments" and make sure it isn't the default output device.
That should pretty much be it, unless you've messed up a lot of settings previously. But Media Center will always indicate whether or not the signal path is bit-transparent. In the header of the main screen, just under the field that shows the track currently playing, there are 3 icons: a repeat, a shuffle, and an icon that looks like a tiny equaliser. This last icon will light bright blue if the signal path is bit-transparent. If you click it, Media Center will show you what is happening to the signal, and how it is being processed (if at all). This is a great way of making sure that nothing is getting messed up. If you've got it right, the volume control on your pc won't have any effect, and system sounds won't come through your speakers. The guys from JRiver say another very good test is to play a DSD track - it will not play at all if you haven't set things up spot on - and if it plays, you can be confident that your settings are bit-transparent.
Another great thing about version 19 of JRMC is that it will convert to DSD on the fly so you can play anything you want using the DSD path through the DAC2. Hours of happy fun!