The first test setup of the new Class-D amplifier project works. We have a fully digital connection between the Raspberry Pi and the amplifier. With the right driver (we have to work on this first), volume and also sound processing can be controlled directly from the Raspberry Pi.
Note: Don’t try to connect the output of an Class-D amplifier to an oscilloscope unless you know exactly what you’re doing. Many Class-D amplifiers use H-bridge outputs. In this case none of the output connectors is directly connected to ground. Connecting one of these pins to the ground of an oscilloscope can create a short-circuit and destroy your circuit and in worst case even your oscilloscope!