HOLLOW EARTH

The Hollow Earth is a sort of waveshaper effect. Extremelly low-frequency waveshaping. It doesn't really affect the harmonics or "tone" of whatever you're playing, but the volume dynamics. Imagine you have a volume pedal and you like to swivel extremelly complex patterns and swells with it. If you do it inhumanly fast, you can make a neat tremolo with crazy variations to the pulses. That's basically what it is!