imaging analog vs. digital input

I have an old pair of monitor10b speakers from the 80s. They still sound great. I've had to replace both tweeters and I rebuilt the crossovers using better capacitors and resistors. This made a noticeable improvement in the sound. I have recently noticed something about the imaging that has me puzzled. I am using a Denon 2802 reciever as a pre/pro, and driving the monitor10s with a Carver tfm35x. My audio player is a Toshiba 9200 DVD and I have it connected to the Denon with both digital coax and 2 channel analog connections. I don't remember the specific Monster nos., but both cables are pretty good ones. Sorry I am not more specific here. The sound via analog outs (using the dacs in the Toshiba) is much better to me overall. It is fuller, seems clearer and the separation of instruments seems much better. It sounds much wider and more open and dynamic than the digital signal. The center imaging however is not as focused as with the digital. Vocals and other sounds that appear to come from "no speaker" in the center of the soundstage with digital, move to the sides when I switch to the analog signal. So, even though the whole sounstage opens up and becomes punchier and more musical, I lose some of the center imaging.

My spealers are about 12 feet apart, out of necessity and I am listening about 10 feet in front of them centered. They are toed in pretty much pointed straight at the listening spot. I think the difference in separation and soundstage is a result of the different signal paths, from dacs to cables etc. between the analog and the digital outputs, but I am looking for some advice on how to improve the imaging and still retain the better overall sound quality I have with the analog connection. I know placement is everything and trial and error is probably all there is, but I thought maybe there are some suggestions I might try. Any help or comments would be welcome.