Can anyone help with an annoying problem of mains hum, I recently made up a lead to connect my casio 6200 to my stereo system using the AUX input, the Casio handbook says this is the port to use, the lead has two mono 1/4 inch jackplugs to two phono plugs, but I find if I turn the volume just above minimum ( on the stereo that is} I get an annoying mains hum, another thing is the Casio volume knob seems to work in altering the volume on the stereo, anyone know the cause of this. thanks.