tannerin
Posted: 6/1/2008 12:30:16 PM
i've found all the links on the ribbon controllers, and i found an oscillator ic. but i'm trying to figure out how to put the two together succesfully. the ic i'm getting is the icl8038, which does square, triangle, and sine wave.
i found this link. http://www.geocities.com/tpe123/
folkurban/synthstick/synthstick.html.
will this work with the ic i'm using? or does anybody know how to make it work.
all your help is greatly appreciated.
i found this link. http://www.geocities.com/tpe123/
folkurban/synthstick/synthstick.html.
will this work with the ic i'm using? or does anybody know how to make it work.
all your help is greatly appreciated.
Posted: 6/1/2008 12:49:33 PM
You will have problems with the 8038, since it does a linear voltage to frequency conversion.
So the distance on your ribbon will vary from one octave to the other. That means that 50% of its length will give the first octave, the next 25% the next one, than 12,5% for the third, 6.25% for the fourth and so on.
So you should have at first an exponential converter circuit before controlling the 8038 in order to get equal spaced octaves.
So the distance on your ribbon will vary from one octave to the other. That means that 50% of its length will give the first octave, the next 25% the next one, than 12,5% for the third, 6.25% for the fourth and so on.
So you should have at first an exponential converter circuit before controlling the 8038 in order to get equal spaced octaves.
Posted: 6/2/2008 4:01:40 PM
You could try a "quick and dirty" approach.
Old HP sinewave oscillators are usually pretty easy to find. You might find old Heathkit oscillators even easier.
These had large vernier type knobs for frequency setting. You would need to replace the large knob with a pulley and create some sort of spring tension arrangement to "rewind" your "ribbon" ... maybe a watch spring or something removed from an old tape measure.
Don
Old HP sinewave oscillators are usually pretty easy to find. You might find old Heathkit oscillators even easier.
These had large vernier type knobs for frequency setting. You would need to replace the large knob with a pulley and create some sort of spring tension arrangement to "rewind" your "ribbon" ... maybe a watch spring or something removed from an old tape measure.
Don
Posted: 6/2/2008 5:07:27 PM
i already have my oscillators, i am just trying to figure out how to make an exponential conversion circuit. i have been searching all night. i have figured out that they're simple, usually two transistors. what i really need to know is how specifically to hook them up, and which specific transistors i need.
Posted: 6/2/2008 6:53:31 PM
Here's a site to explore ...
http://www.electronics.dit.ie/staff/ypanarin/Lecture%20Notes/DT021-4/6LogAntiLogAmplifiers.pdf
Don
http://www.electronics.dit.ie/staff/ypanarin/Lecture%20Notes/DT021-4/6LogAntiLogAmplifiers.pdf
Don
Posted: 6/3/2008 10:31:15 PM
From: Eastleigh, Hampshire, U.K. ................................... Fred Mundell. ................................... Electronics Engineer. (Primarily Analogue) .. CV Synths 1974-1980 .. Theremin developer 2007 to present .. soon to be Developing / Trading as WaveCrafter.com . ...................................
Joined: 12/7/2007
>> Removed 08/June/08 as more useful links given in later posting.
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