Tipto73

I had an old wha VOX connecetd between guitar and Helix input who sucked tone when "off". So, a friend modified wha unit as "true bypass" pedal and immediately I heard a sea of difference. Now the tone is not affected and an the sound is more "open". So, my answer is yes. A not true bypass pedal before digital Helix input "may" affects the tone because cutting some frequencies.