Transvaal Audio - Lost Technology v0.2.2 (Pc/Free)
From the homepage:
Lost Technology 0.2.2 has been released. This minor update replaces the Exp modulator function (which didn't produce very interesting results) with the Top function. There is now a help feature that displays a brief explanation of the most recently modified parameter. This feature is off by default and can be turned on by clicking on a button.

Lost Technology is a VST effect plug-in that separates incoming audio signals into amplitude, frequency and waveform (harmonic content) signals, modulates those part signals and then merges them into audio signals again. The plug-in takes two inputs and produces two outputs. The Analyzer component splits the input signal, the Modulator components combine part signals in various ways and the Synthesizer component merges three part signals into audio output.

Lost Technology is a VST plug-in that runs on Microsoft Windows (it should work on all 32-bit Windowses supported by your host application) and is released under the MIT/Expat/X11 licence.