I bought a Denon AVR 3806 about a month ago on sale at Tweeter. I just opened it up today. In the manual, there are instructions on how to bi-amp. One of the reasons that I purchased this AVR was the great review of the 3805 here and on other sites. In the 3805 review on this site, it was mentioned that if the back surrounds were not used that it was possible to bi-amp the fronts but that DENON was not authorizing/advocating doing this. I do not know if there are internal changes to the 3806 that has prompted Denon to include information regarding bi-amping. In any case, bi-amping a 3806 should not cause any warranty issues.
Dino
PS..I only have fronts currently, I will add the surrounds and a sub-woofer when I purchase a new plasma TV. Feel free to ask questions regarding what is in the owner's manual.
