Here is my version of the Bobtavia. It's an Octavia clone made with a single IC and a transformer. This thing is really wild and works well over most of the fretboard. The Spinal Tapped part came about when I wired the transformer wrong. In Spinal Tap mode, you can recreate the reversed wah sound found on early Pink Floyd songs, such as "Echoes." Or if you have something else on infront of it, or turn the guitars volume down, you can get some wild oscillation sounds! It's a cool pedal and was very cheap and easy to build. It's in an old Rocktek Distortion case that I painted bright yellow, with the old silver Peavey amp knobs.