There is disclosed a power supply stage, and a corresponding method, comprising: a plurality of amplifiers for amplifying an input signal, each amplifier receiving a power supply voltage; a common selection means for selecting one of a plurality of power supply voltages in dependence on a reference signal representing a desired power supply voltage; and a plurality of adjusting means, corresponding to the plurality of amplifiers, adapted to generate an adjusted selected power supply voltage for a respective amplifier tracking the reference signal in dependence on the one selected power supply voltage and the reference signal.