Complex Tone Generator
Machine 4’s main area of specialty is that of complex tone generation. This is achieved by using tunable oscillators that produce richly harmonic rectangular waveforms whose frequency is modulated by signals from other sources.
Machine 4 has two audible “carrier” oscillators that are controlled by two inaudible “modulator” oscillators. The process of having the frequency output of an oscillator periodically changing the characteristic behavior of another oscillator is called Frequency Modulation also known as FM. The modulator oscillators can produce frequencies ranging from very low sub-audio all the way up to audible. The modulators also have four waveform functions that produce four different sounding frequency modulations.
Martian Machine 4 also has a Ring Modulator to accentuate the harmonic sums and differences produced by the two carrier oscillators. Ring Modulators are known for the metallic bell-like timbres they produce.
Machine 4 has two manual control surfaces, one for each carrier oscillator that determines the pitch shift and amount of modulation. Touching the surface pad, when you move your finger position, up and down, the oscillator’s pitch deviation shifts up and down, and when you move your finger position to the right, the modulation intensity will increase. Touching either control surface initiates a gate signal used to activate functions on other instruments.
Machine 4 has two independent envelope controls, one for each audible oscillator. These controls determine the loudness of each carrier oscillator. To turn the audio output off one or both oscillators, simply turn the “Attack” controls fully clockwise for an infinite attack setting.
Machine 4 is designed to interface with Martian Music Machines 1, 2 and 3 and other terrestrial voltage controlled equipment using standard quarter inch jack inputs. It accepts standard 1 volt per octave control voltages use to change the carrier oscillator’s pitch, and gate signal inputs to initiate envelope loudness functions.