Acceleration of electrons in plasma wakefields is one of the prime candidates for complementing or partially replacing conventional accelerator technology, due to its superior acceleration gradients. The plasma acceleration medium is often supplied independently of the acceleration process by e.g. electrical discharging an external current through a gas. Such discharge plasma sources are typically operated at several 10’s of Hz but have also been operated at up to kHz repetition rate. Here, we present the design of a high voltage pulse modulator capable of supplying 10 kV, 400 A peak current pulses at 1 kHz repetition rate into a dynamic plasma load. The pulse circuit is based on a low-loss silicon carbide switch and passive pulse-recirculation, which allows reduction of the power consumption by up to 50% and also monitoring of the energy deposition in the plasma load.