aInstitute of Systematic Musicology
bUniversity of Hamburg
The Hammond Organ with its electro-magnetic generator, still a standard instrument in the western music world. This organ still fullfills the musicians' demand for assertiveness and a distinctive sonic identity with intuitive control of some arbitrary parameters. Bequeathed a heritage of some hundreds of thousands of tonewheel organs to the world, most of them still in service since the original manufacturer went out of business. The worldwide organ scene is still vivid. A description of the tone production mechanism is presented based on measurements taken on different instruments, like Model A and T-Models and includes high-speed camera measurement and tracking of the generator and key mechanisms as well as oscilloscope recordings of the amplifier chain. Some properties emerge due to the interaction of the mechanical motion of interaction with the magnetic H-field. Some non-linear effects like leakage between wheels, changes in the complexion of harmonics and at least amplifier distortion areexamined. A FEM model of the respective geometry showing good accordance with the proposed effects. A simplified FDM-model is written and a more complex physical model having a special regard to the geometry and electronic parts of the sound production mechanism.
ICS file for iCal / Outlook