A loud, large-scale Diapason, nearly always of 8' pitch, invented by Robert Hope-Jones. While Audsley claims that it is constructed in the same was as a normal Diapason, most other sources describe it as having leathered upper lips. Irwin describes the upper lip as having a roll of pipe metal, serving the same purpose as leathering, but being more durable. This treatment, according to Irwin, �gives it a pervasive, dull, round tone that is unfit for use as a base-tone for any type of Diapason Chorus.� He describes it as a solo voice, unfit for hymns or polyphonic music. Maclean describes its tone as �rich, full, and strongly foundational�, and says that it �blends well with other stops of similar pitch and character, but failed to combine effectively with upper octave and mutation ranks�.
Osiris contains ten examples, all at 8' pitch except for one at 16'.