Have my Xbox hooked up to my Yamaha amp via the optical output ( microsoft advanced scart lead ). I'm hearing a low level crackle/hum . This is very unusual for a digital connection. All other sources are fine so its definitely the Xbox. Anyone else experience this? I'm pretty sure I don't get the hum when watching a dvd or playing a cd/wma. Only with games. The Xbox has an xecuter modchip and a 120Gb HD.