Hi, just bought a Code 25, I'm happy with the unit to a degree, but I have one niggling dought that I may have a faulty unit, it seems to be more noticable on certain guitars, when playing my Tokai strat, on the Bluesbreaker presets( 41,42,43), I get a horrible harch distortion ( as though its overloading the preamp, but ony around the 5 and 7th fret of the G and B strings) this also occours with headphones, if I back off the volume on the guitar it does reduce the distortion. Has anyone else noticed this?