Signal tracing is a method to find failure section of electronic circuit. This method is very common in troubleshooting audio electronics, since the tool for injection and monitoring will be very simple and cheap. The tracing method is done by injecting a signal source at one point and monitoring the response at other point, where the signal is assumed to be transferred between those points when the section between them is working fine. The following schematic diagram show a simple signal generator circuit that can be used for signal tracing of audio circuits. This circuit only uses a R and C to make a simple oscillator. This oscillator is used to produce a harmonic-rich waveform for signal injection.