Jack is spot on with trying to determine if it's your speaker or not. One way you can check if it is your preamp section of the receiver is to take a set of interconnects and put them in place of the jumpers of main in and preout. Now go ahead and switch the left and right on the amp section only, if the crackling switches to the other channel then it is the preamp section of the receiver. If it stays the same it is the amp section of the receiver.

Rick


"A fear of weapons is a sign of retarded sexual and emotional maturity." Sigmund Freud