An adaptive sigma delta modulator has an input stage, a conventional sigma delta modulator, and adaptation stage, and an output stage. The input stage produces a difference signal representing the difference between an analog input signal and an adaptive signal, the amplitude of the analog input signal being in a first range [−a+a]. The conventional sigma delta modulator produces an intermediate digital output sequence representative of the difference signal, the amplitude of the intermediate digital output sequence being in a second range [−b+b], wherein b