I'm getting the same problem as the chap in this post from January '13. Via optical to an external (high quality) DAC, I have terrible clipping-type distortion. Very loud, nasty "cracks" on peaks.
I can't find an answer on the forums. It goes away temporarily if I reinstall. Also, it doesn't happen via HDMI to my receiver.
Anybody got an idea? I'm on the latest build. IIRC it started about three builds ago (not sure if that's relevant, though).
Has anyone else noticed distortion when using WASAPI? I have experienced it on two of my systems, on both Win 7 and Win 8, both regular WASAPI (push?) and event-mode.
If I change the output format from WASAPI to either DS or Kernel Streaming, and turn the volume on my soundcard down to around 85%, the distortion goes away.
As mentioned, this occurs on both my desktop system - using a USB headphone amp, as well as my 2 channel "reference" system at home (optical connection from soundcard into a high-end DAC).
Thanks.