the instruō tanh[3] is a three channel waveshaper, limiter, overdrive, and feedback controller.
each channel of the tanh[3] takes a signal input and outputs the hyperbolic tangent function (tanh (x)) for that input signal.
...in more musical terms, tangential distortion is a form of soft clipping which can produce signal amplitude limiting via analogue waveshaping. driving a hot audio signal into it will add warm overdrive.
raw waveforms will be subtly shaped; softening or adding harmonic content based on input amplitude.
understanding what the tanh[3] does to a signal, both mathematically and sonically can be hard to explain, but it essentially adds curves to signals.
for many max/msp and/or pd users, the [tanh~] object may be familiar and is likely a much used secret weapon in many contexts.
![tanh[3]](tanh3.jpg "tanh[3]")