[sdiy] VCO Linear Voltage

[Ian Fritz]

At 10:11 AM 11/17/2009, David G. Dixon wrote:
>Also, I concur that Linear FM is very useful for true FM effects.  Plus, it
>is incredibly cheap and easy to achieve on most synths -- simply sum a +/-
>voltage into the opamp which drives the reference current of the expo
>converter, in parallel with the reference voltage.  In most (if not all)
>cases, this will involve the addition of one resistor and one linear pot.

True, but that method limits you to 100% modulation.  You get a much more 
useful range of sounds with a VCO that is capable of through-zero 
modulation, which can go to 1000s of percent.

Ian