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Ken stone VCO

2006-01-15 by josh summitt

I'm trying to tune the ken stone VCO and have some questions. I realize that
tuning the circuit is tedious but i am using a guitar tuner to try and tune
it. It stays pretty much in tune for about one whole octave and then starts
ti trail off. Is this about average? Also used 2% resistors instead of 1%.
Would this be the reason this the reason? the way i have been tuning it is
different from the way he describes on his site. I put in a cv voltage that
is supposed to be middle C, i then set the 'zero' pot to be middle C. I then
go up an octave and adjust the 'span' so that it is in tune. I then repeat.
Does this sound about right?
Josh

[Non-text portions of this message have been removed]

Re: Ken stone VCO

2006-01-15 by sasami@hotkey.net.au

If you do this, each time you adjust span, the first C will also be
adjusted, so you'll never get it quite right. You need to do it with the
output of the summing op-amp at 0 volts for your "reference" ptich, then add
a volt to adjust for one oct up. After that, you go up a couple more octaves
as the error will be greater with a higher input voltage, then trim it
again. After that, you can set your first C to its correct pitch.

Ken

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>I'm trying to tune the ken stone VCO and have some questions. I realize that
>tuning the circuit is tedious but i am using a guitar tuner to try and tune
>it. It stays pretty much in tune for about one whole octave and then starts
>ti trail off. Is this about average? Also used 2% resistors instead of 1%.
>Would this be the reason this the reason? the way i have been tuning it is
>different from the way he describes on his site. I put in a cv voltage that
>is supposed to be middle C, i then set the 'zero' pot to be middle C. I then
>go up an octave and adjust the 'span' so that it is in tune. I then repeat.
>Does this sound about right?
>Josh
>
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>The CGS Modular Synth home page: http://www.cgs.synth.net/
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>Yahoo! Groups Links
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Cgs synth

Ken stone VCO

Ken stone VCO

Re: Ken stone VCO

Move to quarantaine