errya

Hello all, I hope someone can help me with this problem I am having. As soon as I connect my Helix with the 4 cable method to my ENGL Sovereign 212 amp a hum appears. I can use the clean channel from the amp, because the added noise stays within limits. However, when I switch to high gain the hum gets waaaay too loud. Both my amp and Helix are grounded and my guitar has EMG's installed. I have read about devices that eliminate noise from signals. Would that perhaps solve my problem? Or are there other things I can try? Thanks a bunch! Ferdinand