Old Second Bank Banking & InvestmentsMortgage Old Second Bank Visit Website 1810 DeKalb Avenue Sycamore, IL 60178 (815) 895-1992 (815) 895-0305 (fax) Facebook Twitter About About Drawing on our rich, 145+ year history, Old Second understands opportunity and how to seize it. Whether the economic cycle is spinning or stalled, we have the experience, know-how and solutions to help you START BANKING.