I've just bought a MACBookPro and have a POD HD500X which I can happily use when connected to my amp, ie cable from guitar to Guitar In and then cable from Output to my amp. However, I want to record direct from my POD HD500X onto my Mac using Audacity. I plug my guitar into Guitar In and the USB from my POD to my Mac. I have set Input and Output to my POD but all I get when I hit record is either and awful noise or you can hear my guitar sound but it's so crackly. I have all the latest drivers loaded which Line6 Monkey confirms. Please can someone advise me what I'm doing wrong?