[sdiy] VCO Linear Voltage

[Ian Fritz]

At 08:46 AM 11/17/2009, Jerry Gray-Eskue wrote:

>I see how it would be useful in a LFO for envelope control, but I still do
>not get why it would be better for audio FM patches.
>
>If we setup a patch to vary the pitch at say 440hz by 20 cents using linear
>FM, one octave up at 880hz the variation is only 10 cents, two octaves up it
>is down to 5 cents. So how is this better than using the 1 Volt per Octave
>input for FM to vary the pitch at a fixed 20 cents for all frequencies?

Modulation via expo FM produces a pronounces pitch shift.    This is easily 
audible and has been analyzed in detain by Bernie Hutchins of Electronotes. 
His results were puplished in JASE and can be found in the Electronotes 
Handbook.

Ian