1. An apparatus for emulation of electronic non-linear audio equipment, the apparatus configured to modify a received input audio signal into an output audio signal, comprising: an input interface for receiving an input audio signal and producing a first signal; a dynamic non-linearity (DNL) including at least three static non-linear (SNL) functions, said DNL being arranged such that a mode parameter decides which one of the at least three static non-linear (SNL) functions will be active, said DNL being further arranged to operate on said first signal and produce a second signal; wherein the mode parameter is configured to switch to a first static non-linear (SNL) function under a first set of conditions, to switch to a second static non-linear function (SNL) under a second set of conditions and switch to a third static non-linear function (SNL) under a third set of conditions; a mode estimator configured to receive said first signal as an input, said mode estimator being further configured to determine a mode as a function of at least one previous value of the first signal, and configured to transmit the determined mode to the emulator, wherein the mode estimator is configured to use at least one mode parameter to determine mode switching, the mode parameter is at least one of an energy, an amplitude and a peak value of the input signal during a short recent period of time; and an interface for outputting said second signal as an output audio signal.