AW: Some more ideas on Hammond-Synthesis

[Don Tillman]

   From: Haible_Juergen
   Date: Mon, 10 Jun 96 12:41:00 PDT

   > On the other hand, this one axle (let's say for semitone F#) is connected 
   > to the other 11 axles by gear reduction which should lead to an unstable
   > relationship in phase-terms due to mechanical tolerances and losses.
   > So: (quite) constant phase-difference between equally named semitones 
   > (e.g. f1#- f#- F#), floating free (or *very* 'soft-synced'???)
   > oscillation of the other semitones in relation to our F# (e.g. F#- a).

   Can anybody confirm this? Same semitones on one axis? Would make
   things much easier indeed.

I'm not sure what he means exactly .  Let me try to describe it:

The motor drives a long shaft that's really made of 12 little
interlocking shaft segments (so there can be some wobble between the
individual shaft segments, especially between the first and the last,
maybe 15-degrees or so, though it may not be an issue).

Each shaft segment has two plastic gears, the same size, side by side.
The shaft segment is responsible for a note (say an F#).

Each plastic gear drives two metal gears, both the same size, one in
front, one in back.

Each metal gear is spring-and-friction coupled to each of two tone
wheels, one on each side of it.  That's 96 tone wheels.

So the phase between the eight generator octaves of, say, an F# is
certainly random and can possibly slip.

  -- Don