AV Receiver Underpowered?

In a situation like yours, the easiest way is to listen. Its not hard to hear if an amp is straining. Reading through your post, it most likely is. Since you already have the Denon, maybe keep it and use it as a preamp. It should have preouts for all of the channels. Instead just get a good multichannel amp like Emotiva, or something similar. You'll get a lot more for your money that way and have a better upgrade path if you ever choose to do so.

I did this same thing just a few days ago...added Emotiva multichannel amp and now use my Marantz as a preamp. VERY noticeable change and wish I would have done this a long time ago.

Unfortunately I don't have the pre-outs with the AVR 1908. I don't think I am able to add to this am I? I was assuming I had to replace, just not sure if I need power or it is the "sound" of denon I am missing. It just has always sounded somewhat muted compared to my old onkyo.

I checked out the Emotiva site and saw they partnered with Sherbourn. They have a Sherbourn PT-7020A on sale. It has the pre-outs so I could "add" an amplifier later.

Anyone have experience with the Sherbourn? Would it be a decent upgrade to what I have or should I look to buy something just being released. (I think it's the 1.3hdmi, not sure what 1.4 brings to the table.)