After some time, I managed to solve this problem. It takes a pci audigy 2zs with win10 drivers from daniel_k and to connect some pins on the 40pin header for the extension bay, in order to fool the card into thinking such a bay is connected. Furthermore, spdif pins on said connector need to be connected to a bracket such as those for motherboards headers carrying spdif input signals. The drivers can be set to decode input as dd or dts. This, however, will make the output the sound by the audigy which is not the best possible output device. So i used jriver to open the audigy asio input and tapped into the stream, redirecting it to asio dirac correction software driver and subsequently into a lynx two-b again via asio. Due to all passages being in asio environment, no relevant delay is accumulated. The hard part will be finding motherboards with pci slots in the future.