A control circuit includes: a controller; a controlled system; and a filter for smoothing a return signal. The controller acts on the controlled system vis-à-vis a control signal and the return signal acts on the controller. The controller and the filter are simultaneously adjustable by an adjustment. In an embodiment, the adjustment is made on the basis of a method that includes: measuring or estimating an output signal as a measurement or estimate; transferring, using the measurement or estimate, the output signal into the return signal; determining a power density spectrum of the return signal; and limiting a control signal of the controller such that a power of the control signal does not exceed a predefined limiting value.