The math is simple enough: at idle, the entire regulator circuit including load draws 200 mA and dissipates 112 watts, as 200 mA times 560 volts equals 112 watts; the series resistor dissipates 32 watts, as 200 mA squared against 800 ohms equals 32 watts; the shunting tube at idle dissipates 32 watts, as  80 mA times 400 volts equals 32 watts. But if the wall voltage drops or climbs only 10%, the math looks quite different.  A 10% increase in wall voltage equals a 48% increase the regulator's total dissipation and almost a 100% increase in shunting tube and series resistor dissipation. In stark contrast to the series regulator, the DC sensitive shunt regulator suffers when the load is removed. Where the series regulator is relieved by the load's departure, the shunt regulator burdened by the missing current draw that the shunting tube must supply. For example, if we use the shunt regulator from the last example, then we can rework the math. With the load that draws 120 mA of current, the shunting tube dissipates 32 watts at idle, but when the load is removed, it must dissipate 80 watts, as it must now draw the full 200 mA to bring the regulator's output voltage to 400 volts. Conversely and opposite to a series regulator, when the load's conduction increases, its dissipation drops.

   Other DC sensitive topologies are certainly possible. But in all shunt regulators the key points remain the same: the greater the transconductance of the shunting tube and the larger the value of the series resistor, the better the performance. Bear in mind the potentially destructive increase in current a DC sensitive shunting regulator face when assumptions fail to appear. For example, the wall voltage climbs or drops only 10% from its nominal value, or the load is removed while the regulator is in use. Given a raw DC power supply voltage of 560 volts, a Class AB power amplifier for a load that draws low of 120 mA and a high of 180 mA, a series resistor equal to 800 ohms, and a shunting tube that draws an average of 80 mA.