Its a simple Noise Generator Setup with HP-, LP-Filter, LFO and ADSR with long Attack and Release Times. I like to use the LFO with random waveforms to get some different results in the same pattern. There should be a Compressor or Limiter in the FX Chain.
For those of you who haven't already peeked in the caustic file I posted in >>this tread<< I upload this crazy preset. It generates random noises that sometimes sounds like R2D2 in star wars. Load it and play some random notes on the keyboard and I guarantee some good laugh. Just dont expect to make nice melodies with It