Based off nonlinear compressor but using assymetric shapes. Uses the envelope follower to apply a nonlinear pseudo-compression. Rather than controlling the volume directly the envelope modifies the nonlinear transfer function to apply more or less loudness/saturation. When the envelope is low a heavy tanh saturation is applied (which is like having a good ammount of gain going into the nonlinear compressor), when the evelope increases the curve is pushed down to a linear transfer function decreasing the loudness and the harmonics generated. Thus, transients get the most clipping applied (high gain into the saturation prior to the envelope closing) - quiet parts of the signal get louder (low gain into the linear part of tanh brings up the volume) - loud sustained signals get less saturation (the transfer function goes towards a linear curve for sustained sounds - so their loudness is compressed).