An electrosurgical system including an electrosurgical unit with amplitude modulated output for ablation surgical devices, whereby the electrosurgical unit generates a signal in either a high mode or low mode, both of which are greater than zero, is disclosed. In at least one embodiment, the electrosurgical unit may be configured such that the power delivered to an electrode assembly of an ablation device in electrical communication with the electrosurgical unit is controlled by varying the duration or the intensity of power delivered during the high and low modes, or both. In another embodiment, the duration of the high mode may remain constant while the duration of the low mode may vary in order to vary the power output from the electrosurgical unit.
