• The difficulties encountered with the requirement of very large size of spheres for the switching of higher voltages, the increase of the physical size of other circuit elements, the problems in obtaining high dc voltage for charging C₁ and, last but not the least, the requirement of corona free structure and leads makes the single stage circuit inconvenient for producing higher voltages.
• In order to overcome these difficulties, in 1923 Marx suggested an arrangement where a number of condensers are charged in parallel over high ohmic resistances and then discharged in series through spark gaps.

• The charging resistors R' are always large compared with the stage resistors R'₁and R'₂ ,  R'₂ is made as small as is necessary for the required wave tail. Adding the external front resistor R"₁ helps to damp oscillations causal by the inductance and capacitance of the connecting leads between the generator and the load, if these leads are long.
• It may be readily seen that this circuit can be reduced to the single-stage impulse generator circuit shown in Fig. 28.1(b). When the generator is fired, or in other words, the stage spark gaps have flash over in sequence, the stage capacitors C₁'  come in series in the complete circuit. Hence the total discharge capacitance C₁ can be determined as:

and the effective wave front resistance R₁ can be calculated as,

and the effective wave tail resistance R₂ is given as

where n is the number of stages.

• For this circuit, the wave front resistors R'₁ do not contribute to the discharge process of the main capacitors C'_l The current through R'₂ does not flow through R'₁ and hence does not reduce the initial generator output voltage, the wave front magnitude of the voltage.