I have read the following here
http://theatreorgans.com/hammond/faq/hammond-faq.html:
A Hammond console model manual has 61 keys. The number of tonewheels necessary to produce all 9 harmonics for all 61 keys is 109. Since all console models have either 82 or 91 frequency generators, certain outputs are reused for the upper harmonics of the keys at the upper end of the manual. This characteristic of repeating, for the harmonics of an upper octave, the harmonics used for a lower octave, is called foldback. Most of the console organs also have foldback of drawbar 1 of the lowest octave of the manuals; it repeats the harmonic used for drawbar 1 of the next octave above.
1. There was models Models that have no foldback in the bottom octave (and have a 91-frequency TG)
2. Models that fold back the lowest 9 notes of the bottom octave (and have an 82-frequency TG)
3. Models that fold back all 12 notes of the bottom octave (and have a 91-frequency TG, with 12 complex tone wheels for frequencies 1-12)
I have this feature request: Make it possible to choose the above 3 models + a forth model that reproduce all 109 tonewheels so no foldback is needed and used. That's a total of 4 options for models/ foldback.
