FORT WAYNE - Fort Wayne-based Sweetwater Sound Inc. is planning to add up to 285 jobs over the next three years. The company, which was founded in 1979 by Chuck Surack, has grown to become the third-largest music instrument audio retailer in the country. Construction is set to begin this fall on the first phase of the $8.8 million project that includes expanded marketing and merchandising facilities on the Allen County campus.