sentences:  Following Unimusic's acquisition of Ampeg in 1967, the new company management was actively pursuing the rock market, opening offices in Chicago, Nashville, and Hollywood, and developing products designed to address the needs of rock musicians.When The Rolling Stones began rehearsing for their 1969 U.S. Tour in Hollywood, a power conversion failure blew up all of their UK Fender amplifiers.Their road manager, Ian Stewart contacted Rich Mandella at the Ampeg office in Hollywood, and Rich arranged for the band to use five prototype high-output amplifier heads of a new model being developed by Bill Hughes and Roger Cox.