An equalizer (402) is shown, having a state variable filter in which a first MDAC (502) is coupled to a first integrator (503) and a second MDAC (504) is coupled to a second integrator (505) to allow control of the corner frequency of the state variable filter. The MDACs are each configured to provide variable attenuation in a plurality of discrete steps. A digital attenuation controller is coupled to and adjusts the attenuation of the MDACs independently, and effects a one-step increase in the corner frequency of the state variable filter by first determining the attenuation levels of the MDACs, and then controlling the attenuation levels of the MDACs in accordance with their existing attenuation levels.