Firmware won’t help. The Gen1 isn’t licenced to downmix DTS to stereo.
I simply don’t try to play DTS audio with it. When I rip my discs, I make the AC3 5.1 track the main audio, and just include the DTS track as an option, in case I ever improve my sound system.
Yes, if you have something (genrally an amp/receiver) that you can plug the Optical/TOSLINK cable into, then you’d get DTS 5.1 passthrough.
But, I’d thought it would also passthrough DTS over HDMI – just not downmix it to stereo. Are you sure your audio settings are set to “Digital” and not “Stereo”? Because I was under the impression that the way you were trying should work.
Yes, the Gen2 (and the Live, Live Plus and Live Hub) are all licenced to downmix DTS to stereo, so buying one of those would be one solution.
If I’m mistaken, and Digital HDMI doesn’t support DTS passthrough (although it _ should _), your other option, aside from purchasing a different device, would be to not rip the DTS track when you’re making your encodes. The DTS track is optional, but the DVD must also contain other audio streams – and all those mandatory tracks are playable on the Gen1.
It’s also possible to convert the DTS audio in your files into AC3, which will work on your Gen1. Which program you’d need to do it depends on what file format your files are in – it’s usually pretty easy with .mkv… other filetypes tend to involve a bit more messing about to convert the audio.