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Chapter 26 EVB3 467
Condition
Technical limitations of electro-mechanical drawbar organs with tonewheels cause
some strange tonal artefacts, 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.
Note: Read more about the Click parameters in “Click” on page 468.
Drawbar Leak
Even if all drawbars are at their minimum position, the tonewheel generators of the B3
aren’t completely quiet. This is due to “leakage” of the tone wheels, cross-talking with
the output. Drawbar Leak allows you to set the minimum output level of the drawbars,
when set to minimum. At a value of 0, you can completely eliminate this leakage. At
the maximum setting, drawbar leakage is most definitely audible.
Leakage
Leakage adds a sound resulting from the crosstalk of all tone wheels—including those
of the notes that you don’t play. This provides “breath” to the organ sound.
Crosstalk
The Hammond’s tone wheels are divided into compartments of four—with the same
key, but in different octaves. There are two tonewheels, four octaves apart, on each
rotating shaft. The signal of the Lower wheel contains a small amount of signal,
induced by the higher wheel, and vice versa. This “crosstalk” can be adjusted with the
Crosstalk slider. Note that crosstalk is only audible on certain wheels, avoiding “rumble”
when chords are played.
Random FM
If the tonewheel generator is clean, all frequencies are “straight”—the frequencies are
even/in tune. The three-fold decoupling of the tonewheels—via springs, flexible
couplings and flywheels—is very effective, but can’t compensate for irregularities that
come with dirt and grease in the driving gear. This gradual build-up of grime in the
mechanism makes the revolution of the tonewheel assembly irregular on its axis. This is
transmitted to the tonewheels. The Random FM slider allows you to simulate this effect.
Note: The effect only becomes audible in the higher frequency ranges.