As some of you might remember, Intel has been struggling with the audio passthrough of DTS-HD and Dolby TrueHD audio formats. The issue is in the firmware of the DisplayPort 1.2 to HDMI 2.0 converter chip that is on the Apollo Lake NUC and Kaby Lake NUC mainboards. Intel has sorted out the issue and has released a firmware upgrade that is fixing the issue. The final 1.66 version is available on Intel Download Center. This firmware should also fix some of the issues that are seen with some HDMI 2.0 capable Samsung TVs.
I did describe the upgrade process in my previous post. Unfortunately the upgrade must still be done in Windows and you must have a HDMI 2.0 device (an amplifier or a TV) connected to your NUC during the upgrade. If you don’t have Windows on your PC, you can download a free of charge Windows 10 evaluation version, install that, do the upgrade and then restore your old system. Such a hassle, but can’t really see alternative ways to upgrade at the moment!
To recap, the issue that we were seeing was that DTS-HD or Dolby TrueHD audio formats did not work at all in passthrough mode if you have a HDMI 2.0 capable amplifier. The previous fix was a step to the right direction (they started working at 1920×1200@60Hz mode and 4k modes), but it still did not work ok at 1920×1200@24p resolution.
I’ve tested this update on a NUC6CAYH and it works as expected. I can finally bitstream the audio to my AVR with either Kodi or MPC-HC using any screen resolution.
Follow the discussion at Intel’s NUC community as well.