Pulse Width Modifier is a free exciter and enhancer VST plugin developed by Anarchy Sound Software. Compatible OS(s): Windows.
Pulse Width Modifier uses a procedurally controlled variable length delay line to compress the pulsewidth of the input signal’s fundamental frequency. This acts as a harmonic exciter and an interesting distorter of unrelated frequencies.
http://anarchysoundsoftware.co.uk/anarchysoundsoftware/