Using the EVB3 Drawbar Controls

The EVB3 provides 20 drawbars—nine each for the upper and lower manuals, and two for the pedalboard. The upper manual drawbars are on the left, the pedal drawbars are in the center, and the lower manual drawbars are shown to the right.

Figure. Drawbars.

The drawbars behave like reversed mixer faders—the farther down you drag the drawbars, the louder the selected sine choirs will be. MIDI control of the drawbars is also reversed when using a standard MIDI fader unit.

Essentially, each sine choir is a sine wave that is mixed in at a particular level—determined by the drawbar position. You add sine choirs in this fashion to build up the overall organ sound for the upper or lower manual. This is a basic form of additive synthesis, which is further explained in Additive Synthesis with Drawbars. You can intuitively pick up the fundamental principles of additive synthesis by playing a little with the drawbars.

Two drawbars are available for the bass pedals. The waveform of the bass is not a pure sine wave, like those of the upper and lower manuals. The pedalboard sound uses a mixed waveform, which realistically simulates the Hammond B3 bass tones. The two registers differ in pitch, and in the following ways:

Deactivating Foldback of the EVB3’s 16' Drawbar

The Bass pop-up menu (in the Extended Parameters area, accessed by clicking the disclosure triangle at the lower left of the EVB3 interface) allows you to imitate the non-foldback bass behavior of the first Hammond organ ever made, the model A. This model had no foldback for the 16' drawbar in the lowest octave, with the bottom 12 tone generator outputs available on the first drawbar of the manuals’ bottom octave. On other console organs, the lowest 12 tone generator outputs are available only on the pedals.

To simulate the behavior of the Hammond model A
  • Choose “all the way down” from the Bass pop-up menu.

Without foldback, you’ll find that the sound is more strident, and similar to the pedal sound, especially if you’re not using a real Leslie cabinet when playing the EVB3.