happynow - Reiner's reply is right & wrong at the same time ...
DVD-A discs ALL have either a DD5.1 or DTS track as well as the DVD-A track(s) therefore you can listen to the DD5.1 without a DVD-A player & without having 5.1 analog connections ...
I did exactly that to see what the DVD-A discs were like and they sound very good (as good if not better than a music DVD - like the Corrs Unplugged or Eagles HFO for example)
DVD-A obviously is in another league - which I found out when I went from a DVD player to a DVD-A player
My suggestion would be to buy either Hotel California DVD-A or A Night At The Opera DVD-A (this has a DTS 96/24 track FYI) & see what you think - People I have loaned them to have been gobsmacked -
What prompted me to go the whole hog for a DVD-A player is that most of the extras on a DVD-A are only accessible with a DVD-A player (commentary tracks / video etc - The Queen one has the Bohemian R video in full 5.1 for example)
If you decide to take the plunge let me know & I'll fill you in on the best places to get the discs ...
Regards - Paul