The present invention relates to a method for amplifying a signal in an amplifying device, and in particular to a method for an amplifying device being adapted for a plurality of available powers. The method comprises the steps of: determining an available power (128) by retrieving a value indicating an available power, the available power being one of the plurality of available powers, setting an operating voltage level (130) for a power amplifier (120), the operating voltage level being based on the available power, generating a pre-amplified signal (136) by applying a signal gain (126) to the signal, the signal gain being based on the available power, and generating an output signal (142) by amplifying the pre-amplified signal at the power amplifier.