tanh [3] is a 3 channel independent simple analog wave shaper. Outputs a voltage as if the voltage value were converted by the tanh (tangent hyperbolic) function. Typically, you convert a triangle wave into a shape similar to a sine wave. Also, even if the input voltage is increased (in either direction), it converges to a constant voltage, so it also acts like a limiter.
DEMO
This is a demo that uses tanh [3] for delay feedback. Each time delay feedback is performed, it passes through tanh [3] and degrades the sound. When the amount of feedback is large, it works like a limiter, preventing the signal from becoming too loud.