fluxharmonium
The fluxharmonium is a digitally controlled, electromechanical synthesizer built from the guts of a Hammond Organ. It is inspired by both the mechanism of the Hammond organ itself as well as the Hammond’s predecessor, the Telharmonium. The Telharmonium, designed and built by Thaddeus Cahill at the turn of the 20th century, is considered the first electromechanical musical instrument as well as the first synthesizer.
The sound of the synthesizer is created by the Hammond Organ’s Tonewheel Generator. This is a large metal construction that houses 96 spinning metal discs. Each metal disc has the profile of a sine wave cut into its edge and spins at a constant speed next to an electromagnetic pickup. Since these wheels create simple waveforms, they can be mixed together to create more complex timbres following the principals of additive synthesis. An organ player would do this with various switches and sliders. The fluxharmonium allows for more complex mixing of these frequencies with individual control over amplitude and envelope of each of the 96 tonewheels.
The control system is designed around a Tiny RP2040 microcontroller. The microcontroller accepts MIDI over USB so it can be controlled by standard keyboard controllers or through any software or hardware controller that outputs MIDI data.
