Catalinbread Topanga Spring Reverb Click to enlarge Catalinbread Topanga Spring Reverb Surf s up! And we re all headed to Topanga, our spring reverb pedal based on the legendary Fender 6G15 outboard spring reverb unit! We ve captured all the drip, flutter, cluck, clang, and splash of the original tubes and springs unit in a small pedal format! The outboard spring reverb unit is the sound of surf guitar as well as many other great guitar sounds from the sixties.