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http://www.audioresearch.com/

Audio Research is one of the oldest continually operating manufacturers in American audio. The company was founded in 1970 in Minneapolis with one goal in mind: to advance the state-of-the-art in music reproduction. -Audio Research

The company occupies a 48,000 square-foot, technically-advanced production plant and administrative headquarters in Plymouth, Minnesota, where approximately 50 technical, assembly and support staff guide the product line from concept to finished goods. -Audio Research