Acclaimed makers and restorers Joseph Grubaugh (b. 1950) and Sigrun Seifert (b. 1954) have been working partners for more than 35 years in the San Francisco Bay Area, where they also raised their two children. Sigrun studied at the Mittenwald School of Violin Making, and Joseph studied with Albert C. Muller. The couple met in Los Angeles while working at Hans Weisshaar's workshop before moving to San Francisco to establish their own business.
Grubaugh & Seifert instruments have won multiple awards for tone and workmanship in international competitions, including five Gold and four Silver medals at competitions held by the Violin Society of America, receiving the Hors Concours designation in 1998. Both have presided as judges at the VSA and other international competitions, taught at the VSA's Violin Making and Restoration Workshops at Oberlin College, written numerous articles for The Strad and Strings magazines, lectured extensively, and are sought after for their restoration expertise on important antique instruments. Grubaugh & Seifert instruments are owned by leading players in major orchestras throughout the world.