Thanks, Jason.
I probably will add vibrato, since it simply skips the addition of the dry signal to the scanned signal. Control-wise, I can make the knob be center off, left vibrato depth, right chorus depth. I want to experiment with adding a little LFO’ed low-pass filtering and maybe a little tremolo to make it more realistic. Years ago I actually built a 25-stage LC delay line which was scanned with a PIC processor that PWMed analog switches at the proper tap positions. It sounded great. I could literally emulate the tapped delay line and scanner in code, but it is probably overkill.
I hear you about what it takes to make a truly realistic emulation - one that doesn’t sound sterile. For sure it needs overdrive, from subtle all the way to that iconic Winwood “Gimme Some Lovin” scream. Leakage - maybe. I overdid the preemphasis to the point of almost no key click. It does need to be variable, and I like the idea of using the velocity info.
At some point, the imperfections of a real Hammond become so random that no two sound the same, so what is “realistic” becomes impossible to pin down. For example, the tone generator output levels on my professionally refurbished A100 vary from key to key by as much as two to one.
I probably will try to add a Leslie simulation. I understand the basics, but getting something that doesn’t sound cheesy is difficult. I used to read on organ forums how bad the Leslie simulations were on most clonewheels. And I don’t have a real Leslie to compare to. 