The ST-EQ3 features a balanced bridging input, which may be connected unbalanced if desired. The output driver is 150 Ω balanced, and is intended to drive unbalanced or balanced lines of 150 Ω or higher impedance. Equalization is accomplished by three active circuits, each controlling a separate audio band. These bands were carefully selected to yield a module that works effectively in a wide variety of systems. Setup of the ST-EQ3 is assisted by a peak overload LED which indicates excessive pre or post EQ levels.