Abstract: A system for providing electrical energy to tissue to treat the tissue, including a pair of output electrodes for delivering the electrical energy to the tissue, a pulse forming network for generating short high voltage pulses of electrical energy; an isolation transformer disposed between the pulse forming network and the pair of output electrodes to deliver the short high voltage pulses of electrical energy from the pulse forming network to the pair of output electrodes and to provide voltage isolation between the pulse forming network and the electrodes, and a common mode choke disposed between the isolation transformer and the pair of output electrodes to keep the pulse current flowing out from the first electrode approximately equal to the pulse current flowing back into the second electrode to substantially reduce stray or leakage currents in the tissue.