WASAPI and bit depth question

[CatManDo]

The 24 (or 32) bit output setting will result in bit-perfect output for 16bit files as well, otherwise one would have to change the setting each time when flipping between 16 and 24bit files.

 

This is confirmed by some DAC manufacturers' setup instructions, such as Ayre:

 

Quote

These settings will avoid any undesired signal processing that might degrade the delivery of bit-perfect data to the Ayre USB D/A converter. 

Next if using Windows Vista/7, select "Playback - Output". Choose "WASAPI : Speakers (2- Ayre USB Interface)" for "Device:". In the "Output Format" section, select "24-bit" from the dropdown list under "Output data format:".

https://www.ayre.com/usb-dac-windows-playback.htm#Foobar