Embodiments of the present invention provide an apparatus for amplifying an input-signal. The apparatus comprises a switch-mode amplifier for amplifying a digital input-signal. The apparatus is characterized by a generator for generating the digital input-signal based on the input-signal, wherein the generator is configured to generate the digital input-signal such that the digital input-signal is located at a predefined frequency band and such that distortions are located at a frequency higher than the predefined frequency band.