That is some nasty hiss! I think you might be close to an answer when you mentioned a microphone. Is it possible that you have Tone 2 locked to a tone that uses the mic input and has the volume (tone vol or mic trim) turned way up? Check you Home page display - if the little padlock icon in the bottom row shows locked, turn the little knob beneath it until it unlocks.
thanks man, the thing is..i dont even have a microphone or the dual tone enabled on any patch, i also cheked the in/out config to see if something was wrong but everything seems fine...i am really worried, im thinking bout changing the whole headphone output just to see how it goes with that or maybe reset the thing..im am really clueless..any ideas people?? please...
Try reflashing the POD X3:
In Line 6 Monkey, select flash memory from the updates tab and click reinstall latest.
Line 6 Customer Support