The OxyTone FtoE is a two-channel pedal. A preamp based on that of the Fender® Champ 57 (5F1 / 5E1) with a volume control and an “F to E” control. The Fender® 5E1 saturates faster than the 5F1 which stays brighter at high volume, hence the “F to E” control which adjusts the saturation point from 5F1 to 5E1. And a transparent low gain overdrive based on the famous OxyDrive slightly modified to match the preamp perfectly.