Empress Effects Nebulus - Manual (Page 10)

Advanced Configuration
Entering the advanced configuration: Unplug the power from the
Nebulus. Plug the power back in while holding down both the
preset and bypass stompswitches. The bypass LED should blink
twice to confirm that you are in the advanced configuration.
Modifying the advanced configuration: Each toggle controls a
configuration parameter. When a parameter is modified, the preset
LED will blink to confirm that a change has been made.
Exiting the advanced configuration: Hold down both the preset and
bypass stompswitches. The bypass LED will blink twice to confirm
that the Nebulus has exited the advanced configuration.
Factory reset: While in the advanced configuration, press the
following stompswitches in order: preset, bypass, preset, bypass.
The LEDs will do a little dance to confirm that the Nebulus has been
reset to its factory settings. Please note that this overwrites the
current presets with the factory presets.