I use to have the AV7701, but whenever I had any type of component connected to it, there would be a hum/buzz coming from all 5 speakers. I tested the amp, Oppo, PS3, cable lines and TiVo. I've returned multiple AV7701s, I tried the Oppo as my pre, no noise, I tried a different pre and no noise. Just seems like the AV7701 isn't playing nice with my components.