[sdiy] 60s organ sound

[Ken Stone]

In the case of a neon divider, the dividers are actually relaxation
oscillators running at over 1/2 the speed of the octave higher. As such they
have a sawtooth wave shape. To get the frequency correct, they are
hard-synced to the octave higher. As the neons near their strikec voltage,
the pulse from the octave above is enough to trigger them. When they are
only part way through their cycle, the trigger pulse is insufficient to
cause striking, as such they cycle at 1/2 the rate of the octave above.

Ken

>BTW, somebody claimed that dividers can only produce square waves, because 
>it is "the only binaric (?) waveform", but somebody else claimed that it is 
>possible to make pulse wave dividers and they can be made from the same 
>amount of parts as square wave dividers... Does anybody have any information 
>on this? I suppose square waves can be converted to other waveforms, but is 
>this the only way to get pulse and sawtooth waveforms from a divider-based 
>instrument? At least I think that the tube Philicorda organ might make 
>sawtooth waves directly from its dividers. There's some information on this 
>site about this, but it's in German:
>http://home.t-online.de/home/pam.nickel/bb/7500.htm
>
>Antti Pitkämäki
>
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_______________________________________________________________________
Ken Stone   sasami at hotkey.net.au or sasami at cgs.synth.net
Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
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