This is probably obvious, but I am stumped at the moment. I have a Pro-ject headbox connected up to my avr250 - I picked it up on e-bay to experiment with it - which is fine with turntable and CD inputs, but there is a startling silence when trying to listen to the DVD input. I'm guessing that this has something to do with the digital source? But then the avr250 headphone connection works with DVD - what's the difference? Any suggestions appreciated.