[sdiy] DCO theory

[mark verbos]

wouldn't this make the amplitude change with frequency? does the micro 
control some kind of VCA? Is there an AGC circuit?

mark

phillip m gallo wrote:

>I havent thrown one of my Rolands on a scope yet ( may do that tonight ) but
>wouldnt this make a choppy malformed sawtooth?  Wait. You said Sawtooth not
>triangle.  I'd still think that you couldnt get a clean waveform this way
>or maybe I'm just not groking this yet.
>
>-->No. The Timer output pulse just saturates a transistor to "short" across
>the integrator cap to restart the ramp.  In a analog VCO a comparitor's
>output performs this function.  This is a hybrid  digital modulated/analog
>oscillator.
>
>regards,
>p
>
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