Name: Stroh Violin.
Type: Bowed > Chordophones.
Hornbostel-Sachs No#: 321.312.7
Tuning: G / D / A / E
Inventor: John Matthias Augustus Stroh, 1899.
Country: Many, England.
Region: Continental Europe.
Description: The Stroh violin or Stroviol is a type of stringed musical instrument that is mechanically amplified by a metal resonator and horn attached to its body. The name Stroviol refers to a violin, but other instruments have been modified with the amplification device, including the viola, cello, double bass, ukulele, mandolin, and guitar. John Matthias Augustus Stroh, an electrical engineer in London, invented the instrument in 1899.
Invention: On 4 May 1899, Stroh applied for a UK patent, GB9418 titled Improvements in Violins and other Stringed Instruments which was accepted on 24 March 1900. This described the use of a flat metal [other materials are also mentioned] diaphragm in the voice-box [reproducer] of a violin to mechanically amplify the sound. Then on 16 February 1901 he applied for a second UK patent, GB3393 titled Improvements in the diaphragms of Phonographs, Musical Instruments, and analogous Sound-producing, Recording and Transmitting Contrivances.
Which was accepted on 14 December 1901. This effectively extended the first concept to now use a conical resonator with corrugations at its edge, allowing a more ‘rigid’ diaphragm. His failure to register his inventions in the USA allowed John Dopyera and Geo Beauchamp to subsequently obtain US patents for the tricone and single cone designs used in National brand instruments.
Usage: In 1911 the stroh violin was an expensive instrument. It was offered by the London dealers Barnes & Mullins for nine guineas [£9.45, then equal to $37.80] or twelve guineas (£12.60 / $50.40) at a time when a reasonable factory violin could be had for two guineas. It was listed as being especially suitable for use in small theatres and music-halls. In 1920s Buenos Aires, Julio de Caro, a renowned Tango orchestra director and violinist, used the Stroh violin in his live performances, and was called violín-corneta [cornet violin] by the locals.
Varieties: Luthiers created similar designs, such as Howson, which made brass-horned phono instruments including single-stringed phono fiddles and four-stringed phono ukuleles. The violinophone was made in Prague in the early 20th century. This instrument has a diaphragm mounted vertically in a violin body under the bridge. The sound is carried through a tube to the horn which protrudes from the violin to a long horn which wraps around the shoulder.
A violin that amplifies its sound through a metal resonator and metal horns rather than a wooden sound box as on a standard violin. Willy Tiebel in Markneukirken Germany made Stroh violin copies in the 1920s. The Stroh violin is closely related to other horned violins using a mica sheet-resonating diaphragm, known as phonofiddles. In the present day, many types of horn-violin exist, especially in the Balkans.
Citations: “Stroh Violin”. History Wired. Smithsonian Institution. Archived from the original on May 18, 2016. Retrieved 20 December 2017 ; Real, Sean [19 December 2017]. “The Stroh Violin”. 99% Invisible. Retrieved 12 January 2018. Picture of the duo on their homepage with Heather Trost holding a Stroh violin. Archived September 3, 2011, at the Wayback Machine [archive website].