[sdiy] hammond imitation

[Tim Parkhurst]

You might test this on a real Hammond buy pressing a bunch of keys at once
and checking to see if the speed of the main drive shaft fluctuates. Are you
saying that the pickups might be acting as electromagnets and placing an
extra drag on the tone wheels when a key is pressed? Or are you saying that
pressing a key increases the current draw of the system and causes the drive
motor speed to fluctuate?

Tim Servo

> 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.



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