2009

Table Of Contents
EVB3 Condition Parameters
Technical limitations of electromechanical drawbar organs, with tonewheels, can cause
some strange tonal artifacts, such as crosstalk. These quirks form an integral part of the
B3’s charm. You can adjust the following parameters to define the age of your EVB3.
Condition parameters
Drawbar Leak slider: Determines the minimum output level of the drawbars, when they
are set to their minimum positions. The B3 tonewheel generators aren’t completely
quiet—even if all drawbars are at their minimum positions. This is due to leakage of
the tonewheels, causing crosstalk at the output.
Use a value of 0 to completely eliminate drawbar leakage.
Use the maximum setting to make drawbar leakage most definitely audible.
Leakage slider: Adds a sound resulting from the crosstalk between all
tonewheels—including the tonewheels of notes that you don’t play. Adjust this slider
to add a “breathy quality to your organ sound.
Crosstalk slider: There are two tonewheels, four octaves apart, on each rotating shaft,
for each key (pitch). The signal of the lower wheel contains a small amount of audible
crosstalk, induced by the higher wheel, and vice versa. You can adjust the level of this
crosstalk with the Crosstalk slider. See Tonewheel Sound Generation for further
information. You should note that because crosstalk is audible only on certain B3
tonewheels, any “rumble” when chords are played is avoided.
Random FM slider: If the tonewheel generator of a B3 is clean, all frequencies are even
and in tune. The three-fold decoupling of the tonewheels—via springs, flexible
couplings, and flywheels—is very effective, but it can’t compensate for irregularities
that come with dirt and grease in the driving gears. A gradual build-up of grime in the
mechanism makes the tonewheel assembly turn unevenly on its axis. This irregular
revolution is transmitted to the tonewheels and, therefore, the sound. You can use the
Random FM slider to simulate this effect—which is audible only in higher frequency
ranges.
157Chapter 7 EVB3