Arnearnesson

I've opened up the unit and found that the headphone jack is connected by a 4-pin connector. I will look for a replacement cable tomorrow to see if that is the fault. I didn't see any signs of corosion on the circuits but it can't be ruled out. I don't have an extra interface but i tested the R/L on the back and those worked. Would i be able (worst case scenario) to connect some sort of adapter to the R/L outs on the back and get stereo in my headphones? Like two 6.3mm fused into one 3.5mm, or would that be mono?

I've waited like 20 days for my HD Pro to arrive. I bought it used from a guy who didn't have time to send it until now. It arrived yesterday and i found out it doesn't even work... I use the headphone jack 100% of the time so it really sucked when i found out it's practically useless to me. Money i can't get back. When i plug in headphones all i hear is a high pitched frequenzy note that is just ringing. It's not very loud but it's THERE and it's very annoying. There's no sound coming from my guitar. The noise changes depending on what preset i'm using, some seem to be lesser ringing in some while others clearly increas it. What i've tried: Checked the guitar cable wich works. Updated drivers, firmware, flash. Rollback firmware Turn on the knobs back and forth on all the effects/amps in the presets to see what makes the ringing change but found nothing. Some presets are just more ringy than others. Ringing is there with or without USB plugged in. Tried two different headphone adapters, one cheap but brand new, and one that's better and more expensive. Tried two different headphones. Plugged it in in other outlets in my home but still the same. I don't know what else to try.