My Denon AVR-3808CI has a built-in 130 watt internal amplifier for each speaker. I know not all AVR's are like the older Japan-built Denon's. Would adding one of these amp's make any difference in my case? Based on room size, the 1000 series would be what I need, but at 8 Ohms, the 125 watts this amp delivers is already below what the 3808 claims to supply.
I have a 4311CI rated at 140W per channel with 9 channels. Can it drive all 9 channels simultaneously at 140W, no, not even close. The detailed specs list 9 channels at 140W but right below that list is something they refer to as Dynamic Power and it lists 150W x 2 Channels. In reality 150W with two channels driven is what the amp can really do and in my experience just by looking at the size and weight of the transformer, I would believe that.
Actually with movies having a scene that would demand full volume out of all channels is quite rare I think. So even though the Denon specs are misleading, they could probably defend their claim.
Just about a month ago, I took an ancient Bryston 3B I had in storage and hooked it up to the Denon preamp out of the Front L/R to drive my M80s. This made a significant improvement for some movies. Two movies I can point out are Tron and Super 8. The train crash scene of Super 8 is awesome for testing; there are loud crashing sounds from all speakers. As the Denon no longer had to drive the M80s, it had significantly more power available for the center, surrounds and backs. Overall, adding the Bryston has made a noticible overall improvement.
It's funny; the new Axiom amps arrived just at the right time for me. My 25 year old Bryston (and yes I bought it almost new... sigh, I feel so old) is nice but is a power hog and although still sounds clean is based on technology close to 30 years old. So, after hearing the improvement an external amp makes when used with my fronts, I already have put in my pre order for a A1000.