Playing high definition audio on legacy BOSE Lifestyle product

I recently purchased a house. The previous owner left me his BOSE Lifestyle 48 series complete with built in speakers. I own a Bluesound Vault 2 which contains some high definition audio CD's. When I play the HDCD's through the BOSE a notice a lot of static that is not present when I play regular CD quality FLAC files. After much research I discovered the problem arises from the fact that the BOSE is so old that it does not contain the proper codec to play high definition audio correctly. The BOSE website and customer service was no help. Any idea where I can get a firmware upgrade (even a homebrewed one) so that the system will play high definition audio correctly?
Why not get something like a Paradigm Link, that supports 24/192, to plug into one of the analog aux inputs.  On the cheap, you can pick up a Google Chromecast Audio for $35 that supports 24.96.  Again, you have to plug it into an analog input.

The highest resolution that the Lifestyle 48 supports is 16/44.1, so if someone wrote a new codec, it would down-sample hi-res to 16/44.1 anyway.