Implementation of Julian Parker's digital model of a 
diode-based ring modulator.

Experimental. Implementation does not currently do oversampling.  

For more information:

http://www.acoustics.hut.fi/publications/papers/dafx11-ringmod/
http://recherche.ircam.fr/pub/dafx11/Papers/66_e.pdf
http://webaudio.prototyping.bbc.co.uk/ring-modulator/