This plugin simulates the output you get from an analogue synth's osciallators. You can get a reasonable emualtion of a 303's square (for exmaple) if you set the warmth to about 0.4 and the instability to about 0.05. The frequency is currently a control input, and there is no interpolation. source: http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html#tth_sEc2.7