Clone of the fantastic Schumann Lion X overdrive. It features a beautiful clean blend circuit, as well as twin band pass filters, one for the clean, and one for the drive side. We took this a step further, and added pads for a 9 pin Mini DIN. The build doc includes instructions for making your own expression pedal, so you can actively control the filters remotely. The expression pedal is optional though, and you can build this as per the original.