Squeak, back when you were considering buying the 550 I posted
"------if you can live with just a headphone output "
well, that is the problem, it does not have a true "line out" and you are hearing the noisy headphone amp on your recordings. In some ways I like the 550 better than the more expensive Yamahas,but the lack of a proper output is not one of them. Gary posted some good info, I hope that it helps.
Bill