Do the current Digital Output Cards pass HD audio signals?
The Casablanca IIIHD does indeed process and output HD audio signals with ease. The current Digital Output cards do not restrict bandwidth, and the audio is stripped off the HDMI signal irrespective of any HDCP “hand-shaking” that is going on for video purposes. That does not preclude any restrictions further back up the signal chain, however, including many Blu-ray discs which imply HD audio but often have been found to have no more than legacy Dolby or DTS 5.1 content.