A nanosecond pulser may include a plurality of switch modules, a transformer, and an output. Each of the plurality of switch modules may include one or more solid state switches. The transformer may include a core, at least one primary winding wound around at least a portion of the core, each of the plurality of switch modules may be coupled with the primary windings, and a plurality of secondary windings wound at least partially around a portion of the core. The output may output electrical pulses having a peak voltage greater than about 1 kilovolt and having a pulse width of less than about 1000 nanoseconds. The output may output electrical pulses having a peak voltage greater than about 5 kilovolts, a peak power greater than about 100 kilowatts, a pulse width between 10 nanoseconds and 1000 nanoseconds, a rise time less than about 50 nanoseconds, or some combination thereof.