I tone tested mine through a Marshall JTM45 RI just breaking up. Gibson Les Paul with Seth Lovers. Celestion Redback speakers. The middle toggle position is way louder and brighter than the left and right. L and R is real dark and muffled until the Tone and Voice are cranked up more. In the Left position a couple times it jumped way up in volume and treble, kinda like there's a loose wire??? Right now my favorite tone is the toggle to the Right and adjusted brighter. I like the FAT tone it provides. Its different than my Barber Direct Drive and Super Crunch Box. I think it DOES help get Duane tone.