The Rogue has a "Color" or "Q" control. This is an 86K (measured) slider pot in series with a 4.7k resistor. It replaces the 33k resistor on a conventional pedal. It's great, because it controls the height and width of the peaky frequency boost. A rotary pot would be fine too. At maximum resistance you get an exaggerated Wah effect, great for funk. At minimum it's a wimpy Wah, good for "Tone Control" applications.