tri-amped system that enclosed the power amplifiers and all of the integrated electronics associated with the loudspeakers in an external equipment rack with few or no controls, the settings having all been calibrated at the audio shop. The fully horn-loaded system was used on CCR's final tour. The amplifier enclosure also included preset crossover filters, limiters and equalization. The outside of the amplifier rack was simple: a two-circuit AC power cable connection, XLR connectors for input audio signal, and two 4-pin female twist-lock NEMA L14-30 connectors for carrying the amplified 3-way audio signal to two JM-3 loudspeakers. Bob Cavin was a pioneer in designing and building consoles, and systems designed and fabricated at McCune were being used on Broadway, with touring acts and at Las Vegas show rooms. Taking these McCune sound systems out to Broadway was Abe Jacob, who was an early and influential sound designer. Jacob got his start at McCune touring with Peter, Paul and Mary and several other acts. Abe moved to New York and worked on Jesus Christ Superstar, Evita, A Chorus Line, Beatlemania and many other shows using McCune equipment. Harry McCune Jr. had little desire to grow the speaker manufacturing process beyond the needs of his immediate clientele, which he believed the mass production of his speakers to sell might detract from his core sound rental business. Several McCune employees saw the future of stage and concert audio, and John Meyer later left McCune to form Meyer Sound Laboratories, while Ken Deloria and Bob Cavin formed Apogee Sound. Former employees John Meyer, the founder of Meyer Sound Laboratories Bob Cavin Ken DeLoria, President and founder of the Petaluma-based Apogee Sound Abe Jacob Charles Ginsburg, project leader for the first practical video tape recorder Mort Feld Sound Mixer and General Manager Notable events The Berkeley Jazz Festival Monterey Pop Festival Monterey Jazz Festival Playboy Jazz Festival TED Bohemian Grove 1984 Democratic National Convention in San Francisco XI International AIDS Conference, 1996 The Beatles final Concert Olympic Games, various venues, Los Angeles 1984 References External links AV Universal audio rental services website Audio equipment manufacturers of the United States Manufacturing companies based in the San Francisco Bay Area Loudspeaker manufacturers Electronics companies established in 1932 Manufacturing companies established in 1932 1932 establishments in California Companies based in San Mateo County, California Technology companies based in the San Francisco Bay Area South San Francisco, California 2017