I'm considering getting the NAD T773 receiver and have found that it does not have DTS 24/96. What exactly is this and how badly do I need it on my new receiver-to-be? The NAD has an RS 232 port for future upgrades. Is this DTS 24/96 something I may be able to get upgraded to via the RS 232 port? Sorry but I am quite new to this. Thanks for any help.