I have half a mind to drag my 105w Sherwood RX-4103 stereo receiver out of the garage or even the 50w Onkyo TX-8211 from the den and connect them up to the 80s and see how well they do. Even prior to hookup I'd be almost ready to bet the 80s won't shut either receiver down at comfortable levels.
I can go one better...er, worse, my 14 year old Sony STRD-915(?) dolby prologic receiver. I ran the M80s off of it for the duration of my M22 Ninja XO comparisons when I had the 3808 all tied up with them. The Sony worked very well.