Clavia electro 2 Guida Utente

He filed a patent application in 1940. Don Le-
slie met with Hammond representatives that 
same year and gave them the opportunity to 
buy his invention, but they refused. Instead, he 
started his own company and launched the 
product into the market under the name "Vi-
bratone." In 1946 the name was modified to 
"Leslie Vibratone". Finally, in 1949, The name 
“Vibratone” was dropped and the models 
where named only “Leslie” after its inventor.

Over the years, Don Leslie improved the design and introduced 
a vast number of different models. In 1963, he began shipping 
the Leslie 122 cabinet and it became the most popular model. 
The basic principle behind the Leslie 122 is the incorporation of 
two rotating objects. One is a spinning drum with a deflector 
mounted beneath a downward-facing 15" speaker for bass fre-
quencies -- those below 800Hz. Higher up inside the 122 is a 
compression horn-driver attached to a rotating dual-bell horn 
assembly for mid range and treble frequencies. One of these 
horns is actually sealed; it's only there to serve as a counterbal-
ance. Therefore, you only hear higher frequencies emanating 
from the open-ended bell. The sound is amplified by a 40-watt 
tube amplifier. The 122 also features two rotation speeds: The 
slow speed, which creates a chorus effect, is known as "chorale," 
and the faster speed was named "tremolo." Switching between 
these two speeds at musically appropriate times creates a won-
derful -- and even emotional -- effect. 

Don Leslie, who turned 91 in 2002, 
estimates that around 200,000 
original Leslie 122 cabinets were 
built in total. Laurens Hammond 
himself never liked the Leslie cabi-
net and refused to have anything to 
do with this product. Instead, he 
tried to manufacture other solu-
tions hoping he would make the Le-
slie obsolete, but he never 
succeeded. The Leslie speaker was 
an instant success. Pairing a Leslie 
with a Hammond organ proved the 
perfect match, and this combina-
tion became a "must have" for many 
Hammond organ players.