Ive heard quite a few ppl say they get the same thing. Its far worse when usb is connected to my computer and strange enough, even when the USB port button is turned off, it makes no change in the sound, I have to unplug it. When unplugged its still there but much more faint. Steady 8k tone ringing. Its some kind of interference. If I put an 8k notch eq at the end of the chain in helix it does nothing. I have to put that filter on the other end of the cables, in my interface's mixing software. But, again, when usb is plugged in, that makes little difference because its picked up by the usb cable. Ive got a good usb cable with a ferrite on it. Idk if its the right one, I guess they have different freqs they can target? Ive tried all my cables.
Im about to sell my helix because after way too long putting up with this, trying to solve it. Any help appreciated.