To Enrique : I couldn't find the "non linear" switch in the Kernell page. (may be it is more complicated to adjust...is it ????)
We will post some information about non lineal distortion ASAP. If you have more than one kernel on KERN page you already have non lineal distortion.
The most important things: 1. Energy does not disappear, is distributed throughout the audio spectrum. 2. An audio signal thru a non lineal distortion device summed with a second audio signal thru a non lineal distortion device IS NOT the same that an audio signal summed with a second audio and after send to a thru a non lineal distortion device. Use 1 kHz pure sine and 1.2 kHz pure sine, Nebula with a preamp emulation program with several distortion kernels. Use a FFT spectrum analyzer plug-in and your sequencer for see the results.