Advice on outboard DAC using DVD as transport

A stretch to $500 will get you a used Bel Canto DAC-1.
300 to $400 is probably a MSB Link DAC with upsampling upgrade.

Second Sugarbrie suggestions.

Good suggestion above. I would also highly recommend a used EVS Millenium DAC 1 or 2 if you stumble across one in that price range. Another option is going with even older technology (early 90s) and buying something that was once much more expensive...something like Muse, Theta, Meridian, etc. They may not have the latest D/A chips, but they will have parts quality that you won't find in a newer $300-$400 DAC, which can make as much difference (or more?) as a D/A chip. Some of those units retailed for thousands and haven't held their price well.

Thanks so much for the advice.

I am closing a deal on a Theta DSPro basic one, kinda old, but upgradable. It only accepts Coaxial, so the setup will be---Toslink to my Pre/Pro for movies---Coaxial to the DAC. I am 90% 2 channel 10% movies.

Budget is paramount and the Theta is inexpensive. If this works out I can send the unit in to Theta and upgrade to IIIa.

What about that Sony DVD as transport?

Good sound costs money.Sorry,I guess you already knew that! Thank God for A-gon. I've owned the pro basic2 and the 5a from Theta. The jumps are about the same starting with your 1 . The 2 is in that price range, and much better. Up grades aren't cheap-- AND Theta's 2ch reputation is YEARS old. Everything 2ch from them is WAY behind the pack. The Sony is always going to be a limiting factor (as are most all dvd players) Good luck to you my friend.