Irwin implies that Schulze Diapason is a stop name in its own right, though no examples are known. He says: The Schulze Diapason, named for one of the early English builders (who had come from Germany), is still venerated by builders and organists alike because of its ideal tone. Several magnificent examples of this Diapason are still to be heard in England. Voicers have sought to imitate its tone for many years. Careful measurements, comparison by ear, analysis of its harmonics, and plain guessing have all failed to make an exact copy. The formant of the windchest as well as the pipes themselves seems to contribute much to the tone quality. The tone is animated, �vital,� and seems brighter than the best of the regular Diapasons. Undoubtedly this Stradivarius holds much the same secrets of tonal eminence as the famous violin: a particular pattern of internal resonances which vitalizes the ear without actually being louder or more brilliant with overtones. Physically, both the violin and the Diapason jump into vibration in fewer thousandths of a second than other specimens of their kind. This shortening of the initial period and the steady harmonic structures account for part of the tonal difference. Other factors may still remain secrets. Noel A. Bonavia-Hunt of England has had extensive experience in building and voicing Diapasons of the Schulze design. He relates many interesting facts in the case in his unusually complete book on the organ, The Modern British Organ.