[sdiy] hammond imitation

[jhaible at debitel.net]

Hi,

recently I have run my CX-3 organ thru my Storm Tide Flanger and I used the
Envelope Follower modulation of delay time to get some "outer space"
sounds.

Now with this setup still intact and the Flanger accidentially left in the signal
path, I tried to play an "ordinary" hammond sound. Noticed the Flanger immediately,
and switched it off.

And then switched it on again.

I found that a _tiny_ bit of envelope follower to modulate the delay time (und thus
to modulate frequency) was very pleasant _and_ I even think it makes the Hammond
sound more realistic.

I wonder if this is really true (I have also changed the frequency response with that
flanger, obviously, so the FM effect might not be the important part really), and
if it is true, then _why_?

Is there a mechanisms on a real tonewheel organ that will slightly modulate the
frequency when keys are depressed ??

I really don't think so, but if I make some wild speculations, I could come up with
an idea to explain this. (I mean this phenomenon of which I'm not even sure
that it exists. (;->) )

Here we go: 

The tone wheels are operating with an electromagnetic pickup. If this pickup
is connected to the electronics by pressing a key, it is _loaded_. This load
will draw some energy from the mechanical system.

Now the big question is: Is the electrical load heavy enough? And is the 
propulsion for the tonewheels "soft" enough to cause any perceivable
effect on momentary frequency??

I really don't know enough about hammonds to answer these questions,
and my guess for an answer would be "probably no". But then again
I heard the mixing of drawbars is done with resistive wire (?) and a
transformer, so I guess it's not all high-impedance stuff without much
power consumption, is it?

Any comments welcome,

JH.