I was in need of a function generator to produce audio signals for testing effects / amplifiers; as well as TTL clock signals for digital circuits. As function generators generally cost about £200 new, I decided that I would instead build one myself.
This project uses the XR-2206 integrated circuit to generate the waveform. It can produce sine and triangle waves of selectable amplitude and frequency and also a TTL sync signal fixed at 5V. The frequency range is about 20Hz to 300KHz – so this function generator will easily cover the full human hearing range of frequencies.
There are inputs for controlling the frequency of all the waves and also the amplitude of the sine / triangle wave.
For more detail: Analogue Function Generator
