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Conference Center Organ -- 32' Diaphone Stop

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Low C of 32' Diaphone
Bottom C of 32' Diaphone, with
resonator disassembled awaiting installation

Mitred resonator of Diaphone pipe
Mitred resonator of Diaphone pipe

High-pressure reservoir for Diaphone rank
High-pressure reservoir
for Diaphone rank

Beater box assembly
Beater box assembly for low C#
The pipes of the 32-foot Diaphone stop were originally installed in the organ of the Forum Theater in Los Angeles, California, and later moved to the Kimball organ in the Wiltern Theater, also in Los Angeles.  After being stored for many years in a warehouse in Kansas City, Missouri, they were purchased by Schoenstein & Co. for utilization in the Conference Center organ.

It was originally thought that the pipes were voiced for 15" of wind pressure, but through experimentation Robert Rhoads of Schoenstein & Co. determined that the actual wind pressure was closer to 25".  Consequently, changes had to be made in the organ's winding system, including the purchase of a sixth Ventus blower to provide the higher wind pressure.

Following their purchase, the pipes were shipped to the M. L. Bigelow organbuilding firm in American Fork, Utah, where they were restored and painted in the green hue common to the large wooden pipes of English organs. The firm of A. R. Schopp's Sons of Alliance, Ohio was also engaged to construct a boot assembly to replace a missing boot and beater from the lowest pipe (which may have been claimed as a "souvenir" during the pipes' many years of storage in Kansas City).  And the Ridges Pipe Organ Company of Provo, Utah was hired to releather and rebuild the pneumatic action of the Kimball chests. (Coincidentally, Michael Ohman, president of Ridges, played his debut theatre organ performance on the 4/37 Kimball organ in the Wiltern for the Los Angeles Theatre Organ Society in 1964, and retains fond memories of the organ.)

The Diaphone stop is a somewhat uncommon and occasionally reviled member of the reed family of pipes. It is officially classed as a "valvular reed," and is usually associated with two very loud musical instruments: the theater organ, and the foghorn. (One of the more famous of the latter is perched on the central span of San Francisco's Golden Gate Bridge.) Stevens Irwin writes the following in his Dictionary of Pipe Organ Stops (New York: Schirmer Books, 1965), pp. 73-74:

"The Diaphone just escapes the criticism leveled by some against stops that speak with a pronounced ground tone (fundamental) but without sufficient overtones for blend. The chief function of the Diaphone in almost every model built is to furnish that which no other bass stop can furnish: a completely satisfying, really profound bass tone between CCCCC and C1, not diminished in volume by the tendency of all big vibrating bodies to jump quickly into their octaves. Being essentially a bass stop with a specialized function to perform makes the Diaphone unique among bass ranks. Onto its heavy roll of tone can be placed sufficient 32', 16', or 8' ranks to unify its effect with any combination of stops.

"Many church instruments have had this pedal stop, the congregation no doubt believing they were hearing a Diapason of deep tone, for a great many Diaphones are designed to supplement the flue chorus of an organ, even being called Diaphonic Diapason, which is somewhat of a contradiction in terms.

"The percussive compacting of the air-wave sounds on the ear with an unexpected vigor, enabling it to penetrate any other musical effect known. Evenness and smoothness of voice keep the Diaphone from sounding rough, even by itself. Carrying power and purity of fundamental are also advantages."

Hoisting the pipesHoisting the pipesHoisting the pipes
On-site supervisor Chris Hansford (left) and James Cullen (center and right) hoisting the pipes from the floor of the main chamber to the chests, which are located directly behind the Swell chamber.

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2000 Richard Elliott
(This page was last updated on 23 September 2003 )