Disclosed is a high-voltage generator for an x-ray apparatus. The generator comprises a voltage multiplier having a high-voltage output terminal and first and second alternating-current input terminals, an output transformer coil (12) having first and second output terminals respectively electrically connected to the first and second input terminals of the voltage multiplier, and an input transformer coil (11) having first and second input terminals and being arranged coaxially with and inductively coupled to the output transformer coil. The input and output transformer coils are relatively axially movable. Disclosed is also an x-ray apparatus using the high-voltage generator, a method of configuring a high-voltage generator and a method of configuring a high-voltage apparatus.