In our laboratory, a 1 kJ vacuum spark device is developed as a pulsed X-ray source for X-ray detector calibration and applications such as X-ray microscopy and microlithography. After our previous works for the X-ray emission maximization (up to around 10 J per pulse), this paper analyses the influence of four different triggering systems on the X-ray emission reproducibility. The main conclusion is that a high-power, very fast high voltage trigger pulse is required. In order to fulfill these conditions, a pulse transformer and an air spark gap have been added to the initial triggering device (a magnetic pulse compression circuit). With the new trigger pulse (20 J/pulse, 50 ns rise-time, 22 kV amplitude in an open circuit) a reasonable X-ray emission reproducibility is obtained.