Speaking of drawbars (sliders), I heard that there are only three discreet volume levels that can be obtained for each harmonic as opposed to the 8 levels on a Hammond. Is this correct? And if so, do other parameters respond to the sliders with a higher resolution?

Uncle Dave, did the zipper noise you heard come from the internal speakers or external amplification? Could it have been an issue of another device connected to the keyboard via the audio outputs, or was a computer connected to the USB port of the keyboard? Laptops are notorious for introducing noise (typically the hard drive motor) though the audio output when connected to keyboards, drum machines, etc. via USB. Just curious if the zipper noise you heard is being caused by a similar issue.