A resonator mandolin, also called a "resophonic mandolin," is a type of mandolin that uses one or more metal cones (called resonators) to create sound instead of the usual wooden soundboard (the top part of the mandolin). These instruments are sometimes called "Dobro mandolins" because early versions were made by the Dopyera Brothers, who later created the brand name "Dobro." Today, the word "Dobro" is owned by the Gibson Guitar Corporation. In 1993, Gibson said they would ensure no one else could use the name "Dobro" except them.
The resonator mandolin was created around the same time as the resonator guitar. The resonator guitar was designed to be louder than regular acoustic guitars. A resonator mandolin is usually louder than a standard wooden mandolin and has a different sound and look.
Although resonator guitars are often played on the lap in a style called lap steel guitar, resonator mandolins are almost always played in the usual way.
History
The resonator mandolin was created by John Dopyera, who wanted to make a guitar loud enough to be heard with brass and reed instruments. In 1927, Dopyera and George D. Beauchamp started the National String Instrument Corporation to make resonator guitars under the National brand. Within a year, they also added tenor guitars, resonator mandolins, and resonator ukuleles to their products.
National mandolins were made until 1941. The company also produced resophonic mandolins sold under the Supro brand.
In 1929, Dopyera left National to start the Dobro Manufacturing Company with his brothers Rudy, Emile, Robert, and Louis. The name "Dobro" was a shortened form of "Dopyera Brothers" and also meant "good" in their native Slovak language. This company mainly made guitars but also produced resonator mandolins and resonator ukuleles that used a cone-and-spider resonator, which was different from the one- and three-cone designs used by National. Dobro allowed other companies, such as Kay-Kraft, Harmony (Sears), and Regal, to use its designs, trademarks, and parts. George D. Beauchamp kept control of the National String Instrument Corporation. The two companies had a legal disagreement from 1931 until 1935, when the Dopyeras won the case, and the National-Dobro Corporation was formed. The company moved to Chicago in 1936–37.
Mandolins sold under the Dobro brand had wooden bodies. Mandolins sold under the National brand had metal bodies. After the United States entered World War II in 1941, production of all metal-bodied resonator instruments stopped.
Rudy Dopyera continued to build instruments on his own for most of his life, even into the 1980s. He made a few resophonic mandolins under the Safari brand name.
Variations
Some low-cost mandolins sold in the 1930s and 1940s had a wooden top with a cover plate attached to it using screws. These instruments did not have a resonator cone or a hole for one. The cover plate was only used for decoration.
Blue Comet was a low-cost mandolin brand from the 1930s made by the Regal Musical Instrument Company in Chicago, Illinois. It had an extra wooden sound chamber around the body. This chamber looked somewhat like a banjo tone ring and had several small soundholes covered with metal screens. While the sound chamber might influence the sound or loudness of the mandolin, Blue Comet mandolins do not have resonator cones and are not truly resophonic. They are usually dark brown with F-shaped holes. Similar mandolins were also sold under the Beltone brand and a few other names.
Even though resonators were originally used to increase volume, some modern mandolins now use electric pickups. Some players also add pickups to non-electric instruments and use the resonator only for its unique sound.
In 1938 and 1939, National produced a limited number of "Silvo" electric mandolins. These used the same triangular metal body as the Style 1 resophonic mandolin. The Silvo pickup was placed in a bakelite disc that replaced the cover plate. However, since Silvo mandolins do not have a resonator cone, they are electric but not truly resolectric.
Players
Here is a list of names:
1. Name: Bert Deivert
2. Name: Sam Bush
3. Name: Rich DelGrosso
4. Name: Ry Cooder
5. Name: John Kruth
6. Name: David Grisman
7. Name: Win Butler
8. Name: Steve James