I like gritty distortion. By using a couple of diodes to clip a signal we can build a passive clipper distortion unit. In this example, I use bipolar LEDs to do the clipping. Even though we end up with a drop in audio level it sounds pretty decent.
With a constant current source, we can charge a capacitor in a linear fashion. We examine a simple constant current source circuit and how it works. We also touch the difference between linear charging and based on the RC-time constant.