Thanks guys for all the help.
Matt, you are correct. That is the Andrea USB DAC device in question.
Sorry about what I said. JRiver Media Center software is perfectly fine. It turns out that it's an issue with the USB DAC drivers/software. After installing the Andrea drivers/software, the default format sample rate in Speaker Properties, Advanced tab, got completely locked at 16-bit/48000Hz, meaning it will only accept 48000Hz with the Windows Audio Session API.
Once I realized that the JRiver MC error message is not a bit depth problem at all as first thought, but a sample rate problem, in JRiver MC, I left the bit depth setting at default and made the change to up-sample 41000Hz to 48000Hz. Now, it works with WASAPI. However, this sample rate up-conversion is not ideal. 44.1 does not evenly divide into 48, so the sample rate conversion is a mere imperfect estimation. Sound experts seem to agree that the best sonic performance is when sending native sample rate to the DAC. All my iTunes music is at 41000Hz.
Completely uninstalling the Andrea drivers/software did not bring back the ability to change the USB DAC default format sample rate. I've contacted Andrea support about regaining control of the sample rate.
For the purpose of sending music to this Andrea USB DAC, apparently, it works best with Windows drivers only, not the Andrea drivers/software.
Thanks again for the help. JRiver MC is a great piece of software. In addition, the forum moderators are nice, courteous, and reply fast.
Regards.