The HVG10 high voltage power supply consists of a control box and a transformer multiplier section. The multiplier is a Cockroft Walton voltage multiplier. The output is flat DC (observed many times on my scope).
Measured voltage range is 24kV to 75kV - adjustable via a variac - note that no method is provided for displaying actual voltage. Instead measurements were made with my home built HV probe. I am told by Information Unlimited that by reducing leakage and replacing the balls with 4.5inch diameter ones instead I may get as high as 85kV but my measurement of 75kV was made with no hissing sound or clicking so 75kV is probably closer to my maximum.
I replaced the balls at the output in an effort to reduce leakage. The original ones were 2.2cm in diameter and were getting a bit pitted. I replaced them with 2.9cm balls. I also bent the support for the ground-side ball so that its connection with the ball was on the opposite side from the hot ball. This helped to prevent leakage by the support itself. See the picture below.