What are the resistance specs for the headphone output on the UX2? What range of resistance can the unit support? I was told max 600ohm but I'd like verification..also, how many volts, etc.
(disclaimer: I'm not familiar with Gearbox)
Bad pot on your guitar
Bad output jack on your guitar
Bad 1/4" instrument cable
Are the UX2 Gauges lit up? If not, check the USB Cable.
Did windows perform an update between uses? (PC)