I pulled the 7125 from my system last nite and connected the 7500.Turned the system on and before the amp even turned on there was a hum threw my speakers.The problem was my cable line into the modem,disconnected the coaxial into the box and it was gone.The 7125 doesn't have a ground on the plug so it never had this problem.Fixed the problem tonite with a inline coaxial ground loop isolator($14.95) at local audio dealer.I did call the cable company first thing today and have them coming out 2morrow,will have to call them back and canceal~~~IT'S FIXED!!!!..