A Stroh violin, or violinophone, is a string instrument that amplifies its sound through a metal resonator and metal horns rather than a wooden sound box. The instrument is named after its Austrian designer, John M. A. Stroh. The instrument is louder than a standard wooden violin. This made the Stroh violin particularly useful in the early days of phonographic recording. As regular violins recorded poorly with the old acoustic-mechanical recording method, Stroh violins were common in recording studios. While the Stroh produces significantly more volume, it does this at the expense of a distinctive harsh tone. After record companies switched to the new electric microphone recording technology in the second half of the 1920s Stroh violins became less common.
External links
Smithsonian Institiution - HistoryWired article about the Stroh violin (includes photos)