Dude, it's not mojo problem, it's your power. Some have good power in their home and some dont. Mojo transparent enough to hear your prior chain and power source noise. That's why some get "hum" and some get "hiss", these are all power issue. Try cellphone to mojo to headphone and see if hiss or hum increases or decreases, if there is level of volume changing it's your living home power. Mojo just detailed and transparent so picking it up.