I use two 1/4" cables from my Helix rack to my Presonus Studio 192 audio interface. I decided to use the spdif connection to free up those to inputs and cables. I can hear extra tones (not distortion) on some guitar notes only in the right channel when using spdif on all the presets I tried. I tried two different cables (2 feet and 6 feet) and they do the same thing. I note that the sound is "real" and is recorded to my DAW (Presonus Studio One 3.5). It's definitely not there when using the 1/4" cables.
I set the Helix preset output to spdif, and in the Helix settings I selected digital out and spdif. This is not clipping. It's literally extra tones - not super loud but loud enough that when I'm playing alone I hear it. It's there if I use a mono preset (still only on the right) or stereo preset.
A friend suggested opening a support ticket, but I thought maybe someone encountered this and knows something I'm missing.
Thanks (Win 10, i7-7700, 64 bit, 16 Gb ram, SSD)