[sdiy] string machine technology?

[Ken Stone]

It is common organ practice to generate saw waves simply by adding the
successive sub-octaves via a binary weighted mixer.
The "down side" of this is that the higher octaves have fewer steps in their
waveform, rught up to the top octave at the highest fottage, which is a 1
step waveform, i.e. a square wave.

One way to get the hollow sounding wave shape is to use a 1:4 ratio in your
division. i.e. skip an octave when you mix the steps.

Ken

>Hi,
>
>This is an interesting topic!
>
>richard at skydancer.com wrote:
>
>>Aside from the chorus, the only thing that makes a string synth  different 
>>to an organ is some high pass filtering and soft attack.
>
>What about the waveforms? I had an Arp Omni 2 and I remember it had a swith 
>for "hollow waveform on/off", which sounded like that it switched between a 
>sawtooth and a squarewave. Does anybody have experience with any other 
>string machines?
>
>I know binary dividers create squarewaves, but you can "stack" a few octaves 
>together at certain volumes to get a staired sawtooth waveform.
>
>Farfisa Compact organs seem to use some sorta hard synced oscillators 
>(there's a word for it... "relaxation oscillator"?? or somehing... "blocking 
>osc"? cant't remember...) as "dividers" to create pulse waves that have a 
>sawtooth shape on the narrower part.
>
>(neon lamp organs create sawtooths with their "dividers" but that technology 
>isn't used on string machines I guess)
>
>What ways are there to get sawtooth waveforms on string machines?
>
>Antti
>
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_______________________________________________________________________
Ken Stone   sasami at hotkey.net.au
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