new at this...which amp?

I think the advantage of listening to the B&Ws at the dealer is that you can not only listen to the sound they make, but also what is paired with them, esp the source. I have not found a DVD player that can match dollar for dollar what you can get in a stand-alone CD player. There are so many that its hard to recommend, but may I suggest that you poll Audiogon members for which CDP they are playing with your exact speakers. I hope that your dealer has a listening room that is similar to yours. Its always "apples and oranges" but maybe you can get close. You will get several hundred recommendations for CDP! After all, we all think we made the right decision! But it will be your ears that will decide. Your money is best spent on a really good CDP instead of using the DVD. That may solve your issues, or at the least give you great sound. I think the B&Ws are simply projecting what they are given. By the way, I had ADCOM and didn't care for it, however, I helped a friend buy a nice system and he went with Rotel and I love his sound. He has a Rotel pre-amp, Rotel amp and B&W speakers (I can't remember which, but the tweeters are all similar and it sounds like the high frequencies are what's bothering you). Good luck and have fun shopping around!

How to fix a room - www.auralex.com. Send a drwaing or picture of your room with dimensions, openings, etc. At no charge they will make recommendations on what you should try.
Amps - In order to get twice the volume, you need 10x the power (sound is logrithmic). Doubling of the power will supply a "just-noticable-difference" in sound volume.
You don't want to be going into the complexity of bi-amping, when you have enough of the fundamentals it appears like you need to take care of first.
The easiest way to get loud and clean - get more efficient speakers.

If I want to eliminate CDP as the problem, is Denon 3910 a good choice?

Try searching the forums under digital. Use key words like "smooth, analog, sounding, best" etc...

A single disc stand alone cd player will give you better results over a combination dvd/cd player. If music is your objective, then go for that.

I found a few comments regarding Adcom gear as a bit on the bright side. Perhaps they ARE contributing to your problem? Still, there is a lot you can try for less $$$ before making that move.

Most dealers don't loan gear out like the "old days." You will be lucky if you have dealers that even cary the brands and models you may be looking for. Most used gear can be bought and sold through Audiogon with little or no loss. Consider the price for ads and shipping your rental fee for trying stuff out.

Good luck,

The Denon 3910 is an excellent universal player, but in stock form it does have a house sound. You may like that sound and you may not. If you are planning on upgrading the source, lay out some of your parameters (type of music you listen to, the sound you like, whether or not you require a universal player, budget), and be specific as possible. You will again might get many suggestions, but it will get you much closer toward choosing the source that will meet your preferences.

If you can live with a stand-alone CD player, for the price range of the Denon 3910, you might consider the Jolida JD-100A (tubed player, the Ah Tjoeb (tubed player), the Musical Hall (forget the model number), or the Quad CDP. There are other options as well, but any of these with a good pair of interconnects will likely calm a good deal of the harshness you are hearing.

Finally, I would definitely go hear the B&W's at the dealer. I've heard the CDM NT7 with a highly musical amplifier, and an excellent source, and the music sounded a bit choked and harsh. I attributed it to the speakers, but I could be wrong. Go hear them with good ancillary gear and see what you think.

OK, REALLY finally this time. Zee room, zee room, zee room. Start there first. I hope I've helped. You've received some excellent advice here from the other respondents.
All the best,
Howard