An energy module (1004, 1191) for generating electrosurgical energy, ultrasonic energy, or a combination thereof, the energy module comprising: a controller; a first power amplifier circuit having an input and an output, wherein the input is coupled to the controller and is configured to receive and amplify an input signal to generate a first output signal into a load coupled to the output of the first power amplifier circuit; a second power amplifier circuit having an input and an output, wherein the input is coupled to the controller and is configured to receive and amplify the input signal to generate a second output into the load coupled to the output of the second power amplifier circuit; wherein the first power amplifier circuit is a wideband power amplifier circuit and the second power amplifier circuit is a resonant power amplifier circuit, wherein the controller is configured to generate a waveform having a predetermined wave shape and frequency based on the load coupled to the output of the first or second power amplifier circuit (1006, 1008), and further comprising a digital-to-analog converter coupled between the controller and at least one of the first and second power amplifier circuits, wherein the digital-to-analog converter is configured to receive the waveform in digital form and provide an analog waveform to the input of the at least one of the first or second power amplifier circuits (1006, 1008), characterized in that a power rating of the first amplifier circuit is different from a power rating of the second amplifier circuit; and in that the controller is configured to select the first or the second power amplifier circuit based on power to be produced in the load. a controller; a first power amplifier circuit having an input and an output, wherein the input is coupled to the controller and is configured to receive and amplify an input signal to generate a first output signal into a load coupled to the output of the first power amplifier circuit; a second power amplifier circuit having an input and an output, wherein the input is coupled to the controller and is configured to receive and amplify the input signal to generate a second output into the load coupled to the output of the second power amplifier circuit; wherein the first power amplifier circuit is a wideband power amplifier circuit and the second power amplifier circuit is a resonant power amplifier circuit, wherein the controller is configured to generate a waveform having a predetermined wave shape and frequency based on the load coupled to the output of the first or second power amplifier circuit (1006, 1008), and further comprising a digital-to-analog converter coupled between the controller and at least one of the first and second power amplifier circuits, wherein the digital-to-analog converter is configured to receive the waveform in digital form and provide an analog waveform to the input of the at least one of the first or second power amplifier circuits (1006, 1008), characterized in that a power rating of the first amplifier circuit is different from a power rating of the second amplifier circuit; and in that the controller is configured to select the first or the second power amplifier circuit based on power to be produced in the load.