Well, got the 770 Amp yesterday, got everything hook up to the 990. Worked fine...for about an hour. Listening at a lower than normal volume and heard 3 loud "POPS" coming from the left surround. That channel is gone because I used another channel to check that it wasn't the speaker. Hopefully, it didn't do any permanent damage to the speaker. All in all, when I had to leave a message on the ansering service that I probably won't get a response until Monday, I am not at all happy. Next I get to lug that heavy back upstairs that nearly killed me getting down. Sorry for the venting!