I would like to build a circuit that adds a "vibrato" audio effect to a simple sine wave input.
Sample audio clip from Wikipedia: Vibrato, Sound Frequency 500Hz, Frequency Modulation 50Hz - Vibrato Frequency 6 Hz https://upload.wikimedia.org/wikipedia/commons/e/e7/Frequenzmodulation.ogg
This sample effect is exactly what I want to create. I already have a circuit that generates a sine wave, and I can easily generate a 50 Hz frequency modulator. I'm just unsure of how to create a circuit that would provide that 6Hz vibrato effect and combine everything together to get the desired sound.
Does anyone have any ideas of things I can try to replicate the sample audio with the effect?