should i listen to cs's on dvd or cd player

As the fruitcake lady would say: "for Godsake man, try them both and use the one that sounds better".

Gmarcotte:
Don't have any experience with your units. But as Elgordo said have to try.
Interesting chance you have in comparing those players.

Use the same connection to compare both with either analog or digital. In the first case you'll be comparing the digital to analog conversion capability of the players.
If you can use optical or coaxial digital to compare both under same conditions you'll be having the comparison of their performance as transports.

Keep in mind that you can compare them right now. The newer unit should improve it's performance after couple hundred hours of use.

The newer unit would be expected to perform better than the older one but in audio you can have nothing for granted. Trying is mandatory.

I wouldn't suggest it.

Elgordo, Damn good response man! Damn good response Indeed!

The answer is from the reponse above...the one that sounds best to you. I can tell you that my wife "had to have a changer" so I bought her a Yamaha and I will tell you that upon listening I thought it was a very "polite" player in that it seemed smoother than other inexpensive player I had listened to and in CD, erroring in politeness is a good thing. I doubt that spending much money on cabling at this point will change much sonically. Your speakers and amp must be very revealing and the CD player must be able to extract the smallest nuances to hear the differences there "might" be. In these cases you would own similar items that are rated Class A, B, and possibly C to look that deep into the sound stage. When you look at the investment in gear most good reviewers own you can understand how they "might" hear the differences in cable. Do not let the hobby have you agonizing over what should be great joy...listening to music you love.

i have been listening to the yamaha for 10 years and have never seen the need for upgrade. i have listened to the onkyo for a couple of months now and it sounds the same except for some strange noises at the start of playback. similar to other cheap dvd players i have delt with. i just thought todays d/a converters would be substantually better.