I need advice on upgrading my DVD player

Are you using the Denon's analog outputs, or are you letting the AVM 30 process the audio for CD's and DVD's? If you're using the analog outputs, try a digital connection to the pre/pro and let it decode the DVD's and CD's. (You won't be able to do that for SACD.)

What is it about the sound that you currently don't like? Is it different from using other sources, such as a tuner or turntable?

If you do think that you want to upgrade the source, consider these possibilities:

1) Leave the Denon as it is and use the pre/pro to process the digital signals, or consider upgrading the pre/pro and continue to use the Denon as a transport
2) Consider an external DAC. This will basically only work for CD's, but will give you the flexibility of using computer-based audio, although you already have that to some extent using your pre/pro.
3) Change out the Denon 3910 for a "better" multi-format player. I can't comment on how the sound would differ with your current 3910.
4) Get the 3910 modded. There are a couple companies that do this.

I know that I've introduced more questions that answers, but I'm just trying to provide an overview of options.

Michael

What happens when you use the pre/pro and digital connection for CD's? Do you find that it suits your tastes any better or worse?

What do you feel is deficient in the sound that you're currently getting through the Denon?

Michael