Bought a vintage nad tuner to be used in my garage system, hooked it up to the Yamaha to try it out, hooked everything up and powered on the tuner before turning on the yamaha and heard a loud pop. Disconnected the tuner and fired up the Yamaha and there is a definite hum in all modes and very low volume and loads of static when turning the volume switch. As you can imagine I am sick to my stomach, the yamaha is about a year old. Any idea how bad this damage could be?