Stroh violin

Stroh is a maker using Stroviols, as a trade name for their phono instruments which includes violin, viola, cello, bass, ukulele, slide guitar, mandolin. There are also numerous Stroviols one string phonofiddles made. These instruments are named after its designer, John Matthias Augustus Stroh, an electrical engineer in London, who patented it. 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 anologous 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. The Stroh violin is also closely related to other horned violins using a mica sheet-resonating diaphragm, known as phonofiddles. Willy Tiebel in Markneukirken Germany made Stroh violin copies in the 1920s. Only instruments made by Stroh can be called Stroviols.