Hello,
I've built a TV-server with a DigitalDevices Cine C/T and DuoFlex C/T. 
The DuoFlex is connected with the small flat cable to the Cine card. 
I installed the media-build-experimental-dkms drivers. 
tvheadend shows only the two devices from the Cine C/T the DuoFlex C/T is not shown. 
I removed the flat cable between the two cards to check it out. 
Is there an issue with the new bought cards or is there a configuration error?
Yours Tolotos