dSpec Direct Spectral Synthesis VCO

dSpec is a two channel digital voltage controlled oscillator that generates 
waveforms using additive spectral synthesis. This means that the waveform is built 
up from a set of sine waves of various frequencies and amplitudes.  
The pitch of each note is defined by a sine wave at the notes’s fundamental 
frequency, for example middle-C on a piano keyboard has a frequency of 261.63Hz. 
The harmonics, also called partials, are sine waves with frequencies that are odd or 
even multiples of the fundamental frequency. The timbre or sound of the note 
depends on the amplitude or loudness of these harmonics relative to the 
fundamental frequency. The waveform can also include sine waves unrelated to the 
fundamental frequency adding to the range of sounds that can be synthesized. This 
set of sine waves of various frequencies is called the spectrum of the waveform, 
hence the term spectral synthesis. 
The amplitude of the harmonics can be modulated in various ways to dynamically, 
and sometimes radically, change the sounds that dSpec synthesizes.