1. An amplification stage comprising: an input scaling block for scaling an input signal in dependence on at least one scaling factor to generate a scaled version of the input signal; a power amplifier for amplifying the scaled version of the input signal; an envelope detector for generating an envelope signal representing an envelope of the input signal; a non-linear mapping block for scaling the envelope signal in dependence on the scaling factor to generate a shaped version of the envelope signal; and a modulator for generating a power supply voltage for the power amplifier in dependence on the shaped version of the envelope signal.