DAC on Universal player

I recently purchased the Tri-Vista 21 and it made a marked improvment over my Denon DVD-3800. I now use the DVD-3800 as a transport most of the time exept for DVD-Audio. I think the biggest difference is in the smoothness of the midrange and treble regions. Also, the bass seems to be more solid and defined. To help you gage this response, I am in the middle of a major upgrade cycle so I still have a lot of tweaking to do to get things just right. Right now my system consists of...

Revel M-20
BAT VK-300x SE
REL Stadium III
Denon DVD-3800
MF Tri-Vista 21
Better Cables Digital Coax and SE RCAs
Kimber Kable 4PR Speaker cables

Hope this helps.
Dave

Arthursmack, you just beat me to it! I was going to ask the same question just about now. The only difference is that my universal player is Sony 999ES and my Pre-pro is Bryston SP-1.7.
I was reading good reviews about Channel Islands DAC with upgraded Power supply. There was one, modified by ModWright, for sale recently.($450).
I am wondering now, would it be an improvement over your Denon or my Sony? Regards.

I'm doubt that stock Marantz 8400 would have any significant advantages over Denon, I'd rather get it modded or, indeed, would consider good outboard DAC.
BTW, are you sure you really have to deal with universal players at all?