I want to sing a harmony vocal and create more harmonies, is this possible?
Our Harmony processors were not designed to make harmonies from a harmony vocal. It is always recommended that the lead vocal drives the harmony portion of any processor.
When we build harmonies we reference the incoming lead vocal along with the chordal information from the instrument/Aux input, MIDI or Manual Key and Scale entry. The issue here is that the unit doesn't have a reference of the lead vocal so it has no way to build the harmony correctly. If you sing a harmony vocal into the unit to drive the harmonies, it will in many cases actually give you an incorrect harmony depending on what note you are singing around the lead vocal.
The exception to this is to use notes node on the units that offer this feature. With notes mode, the unit follows incoming MIDI information exactly so whatever is played on the MIDI device will determine the notes that are generated in the harmony.