Im new so pretty clueless......but.......my bed time reading for the last few nights has been the manual, and I did notice a section about the bypass being configurable to DSP bypass and analogue bypass....Quote from manual below...Could it be that you are in dsp mode, which may colour the tone a little?. Page 10 of the Helix HX manual NOTE: There are two types of All Bypass for the HX Effects device: Analog bypass (sometimes called "true bypass"), where mechanically