If you are completely satisfied with your current sound, why change? You do have preouts for all channels which gives you the option of adding external power amplifiers if you want improvement though.
The fact that you bothered to post, however, suggests that you may not be completely satisfied with what you hear at present. Your Yamaha has reasonably good amplifiers, but there are certainly better-sounding ones out there if you are willing to spend the money; the $30 per channel or so that Yamaha spent on those amplifiers certainly does not result in the superior sound quality that top-quality amplifiers can produce. Amplifiers of that type will usually produce more than 2% distortion on peaks in normal operation when driving 7 channels, which is not obnoxious but certainly a sound quality issue.
Achieving very high sound quality is not about volume or power as much as ultra-low harmonic distortion and also the extremely low output impedance that allows the amplifier to maintain extremely high linearity over varying speaker impedances at different frequencies. Those who are not knowledgeable about the interaction between speakers and amplifiers think that one amplifier is pretty much the same as another; they have obviously never done design and testing of amplifiers and learned how totally wrong that is!
There are not very many power amplifiers available for under $2000 that would be a huge sonic improvement for you IMO. I use a Bryston 3B-SST, which would, if used for your front speakers, give you an improvement that would IMO be a readily audible and excellent upgrade, but it does cost $4300.
There is ONE amplifier for under $2000 that I CAN recommend to you, however. The Vincent SP-331 is only $1300, and that would be a very nice upgrade if you added it to your front two channels. It was voted "Product of the Year" by the editors of The Absolute Sound and is quite an amplifier for its price. I think that you would probably find the improvement worth the price.
Originally Posted by AC2011
Recently got my 7.1 going. Room is approximately 19 x 22, NOT dedicated to HT only. Using a Yamaha RX-A800 (rated 95WPC). Speakers are rated 89dB. (Boston Acoustics L/C/R and front presence/height, with Fluance bi-pole surrounds).
I don't listen at reference level, and have not had it anywhere near a level where I've heard any straining/clipping.
But, read lots of posts relating to speakers that said adding clean external power really helped to "open them up". To me, this suggests that maybe there is even better sound to be had at my listening levels, without having to go to 11.
So, what say you - is adding an amp worth the time and $$?