An apparatus for amplifying a transmit signal comprises a transmit path comprising a power amplifier module to be coupled to an antenna module. The power amplifier module is configured to amplify a transmit signal. Further, the apparatus comprises an envelope tracking path comprising a variable delay module and a power supply module. The variable delay module is configured to vary a signal delay within the envelope tracking path according to a delay control parameter. Further, the apparatus comprises a delay control module configured to provide the delay control parameter based on a current characteristic transmit frequency of the transmit signal.