I wanted to weigh in on the "Hiss" problem. I used my Helix for church worship. This was the 1st time for live use. I went out mono XLR (set to mic level) direct into the house sound system. I was emphatic about phantom power being turned off for my channel. The extreme Hiss made using the Helix XLR output impossible. I tried pressing the ground lift and that made no difference. The Helix internal phantom power was turned off (not that that would make any difference at all). My main output volume was turned all the way up, but interestingly enough, it did not make any difference where the volume knob was the extreme hiss was the same. Same goes for volume pedal position. With volume pedal heel down or heel up the extreme hiss was the same. The work around was to go 1/4" mono out to DI which completely cured the problem. After rehearsal the paid sound tech and myself spent an hour trouble shooting to only discover #1. Phantom power was off #2. There were no bad cables. #3. There was no problem with the stage snake. #4. There was no bad channel on the mixing board. #5 The only way to get rid of the extreme hiss was to go with 1/4" out into DI. Very disappointing for the first time live experience. The funny thing about this situation is that at home I go stereo XLR out into CH1 & Ch2 of my Yamaha MG16 inexpensive mixing board. There is a small amount of hiss but nothing like what I experienced at church. So, in my case, it doesn't appear that the hiss is caused by phantom power at all. Maybe power is the culprit here. It would be nice for Line 6 to weigh in on this problem.