Denon (株式会社デノン, Kabushiki Kaisha Denon) is a Japanese electronics company started in 1910 by Frederick Whitney Horn, an American entrepreneur. Denon produced the first cylinder audio media in Japan and players to play them. Decades later, Denon was involved in the early stages of development of digital audio technology, while specializing in the manufacture of high-fidelity professional and consumer audio equipment. Denon made Japan's first professional disc recorder and used it to record Emperor Hirohito's voice. For many decades, Denon was a brand name of Nippon-Columbia, including the Nippon Columbia record label. The Denon brand came from a merger of Denki Onkyo (not to be confused with the other Onkyo) and others in 1939. In 2001, Denon was spun off as a separate company with 98% held by Ripplewood Holdings and 2% by Hitachi. In 2002, Denon merged with Marantz to form D&M Holdings. On March 1, 2017, Sound United LLC completed the acquisition of D+M Holdings.