Why does my Denon 5910CE transport not sound good?

I've tried the Denon as a transport CD-player for my new Bel Canto dac3. I swear, an optical connection from my Mac computer, using iTunes, sounds far superior. More channel seperation, a wider frequency range and a great soundstage.
The outputs of my dac3 are running balanced into a Mcintosh MC275. I was hoping for it to be a jack of all trades, but if it doesn't cut it as a CD transport..... I am wondering if it has something to do with the Denon being a single ended, unbalanced machine.
I've heard Sony's make for good CD transports. Any wisdom would be greatly appreciated.
Are you using the optical or coax connection on the Denon? You should if you really want to compare. Balanced won't matter with the digital outs. Mine sounds great as a CD player. I'm sure there is always something better but the digital outs will depend more on the quality of the DAC than the transport.
I tried both the optical and coax digital outs on the Denon. The DAC I'm going into is the awesome Bel Canto dac3, so it sure isn't the DAC that's the issue.
Trying the optical going out of my Mac sounds really good, and perhaps I should just sell the Denon 5910. Perhaps there may be some setting that is off in the Denon though - it has a multitude of controls, and I just received it yesterday.
Perhaps some burn in is needed? From what I read the big reason to buy one of these is the video performance. (as in one of the best out there.) It wouldn't surprise me that a decent stand-alone cd/sacd player might out perform the Denon. I own an Arcam which the mags raved about (audio and video/wise)but I never played more than a couple of cds on it.---At that time I had the Theta Gen 5,A,+ the 24/96 mod.
There is a reason some pay 10k for a transport/only.
thanks guys.
I've heard that the Sony CD transports are excellent. The Rotel RCD-1072 has one, and reviewers on Stereophile have used them as CD transports for auditioning equipment.
I beleive the Denon has a Pioneer transport.
May be the laser was optimized for reading SACD layer?
As an SACD player, it still one of the best for under $1000 ?