I definitely didn't do any research, but I am thinking that the AES/EBU on my soundcard is capable of handling a stereo uncompressed signal and the db25 handles up to something like 16 stereo uncompressed signals. Theoretically, if the device that decodes the DTS signal sends it to a db25 output, these outputs are in uncompressed digital format. My soundcard could theoretically record two channels at a time. Also, to take it a step further, I think you can convert from AES/EBU to S/PDIF. So you wouldn't even need my sound card. You could hook up to the correct two pins on the DB 25 connector and have an rca cable on the other end (maybe with some electronics in between if necessary) and record the digital signal on a sound card two channels at a time. Just do it 3 times to get all 6 channels, time sync them, and combine them into one big file.

Again, all theory. Just wanted to share it before doing any research.

Edit: After a quick search, I am at least partially right: http://tcsupport.custhelp.com/app/answers/detail/a_id/1305/~/interfacing-aes%2Febu-to-s%2Fpdif

I know my RME soundcard can handle the bits mentioned in the article. I am not sure about standard cheapy ones for PC's.

So this could be done fairly simply in theory.

Edit2: Another interesting link http://taperssection.com/index.php?topic=153934.0

Make the cable in the first link (or just use something like my soundcard that already works with AES/EBU) and attach it to the cable in the second link and voila - record 2 channels at a time and move the S/PDIF cable to each AES/EBU output in the other cable and start over until you get all of the channels recorded.