2009

Table Of Contents
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.
Upper manual drawbars Lower manual drawbars
Pedal 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:
The left, 16-foot register (derived from pipe organ lengths) contains more octave
harmonics.
The right, 8-foot register has a more prominent fifth portion (fifth harmonics are
enhanced).
145Chapter 7 EVB3