Got the headphones working. Just removed all cables and replugged, now it sounds fine and dandy!
Plugged in on the front input. Amp setting.
Removed all distortion on the marshall. Sounds veeeery distorted and low. Yeah, Reading the manual but didn't get any help from it yet when it comes to this subject in particular. But yeah, I do recognize the need to read it.
Settings on the POD;
Input, Guitar. Output, Combo Pwr Amp (tried everything, not sure what is the correct setting however). Really appreciate the help, and quite impressed how ..fast you answered... Thanks again