A supply pump actuating turbine, in particular for a power plant, that includes at least two jet sectors for introducing a working gas into the turbine, a line system for connecting the at least two jet sectors to at least two different sources of working gas, and a valve arrangement for setting the supply of the jet sectors with the working gas from at least one of the sources. After charging the control node of the switch transistor at the first charging rate, the control node of the switch transistor is further charged at a second charging rate until the control node of the switch transistor reaches a target signal level, where the second charging rate is less than the first charging rate. The first audio conversion circuit generates a first pulse width modulation signal according to consecutive values of the first audio signal for configuring a first power stage circuit.