[sdiy] Digital accumulator VCO core?

Brian Willoughby brianw at audiobanshee.com
Wed Feb 10 00:33:17 CET 2021



On Feb 9, 2021, at 02:40, Neil Johnson wrote:
> Hi,
> 
>> I was wondering if anyone ever experimented with replacing the
>> accumulator core with a digital setup. Essentially you would have
>> control voltage turned into current being shunted to ground, and you'd
>> sample this current with the ADC, accumulating it in software.
> 
> This could be easy to do with a shunt resistor feeding into a
> transimpedance amplifier and then into the ADC.

Why is the trans-impedance amplifier needed?

If you feed a current into a shunt resistor then you already have a voltage for the ADC. About all you need after that is a voltage follower to provide a low-impedance source for the ADC, assuming it requires that.


> But please do:
> "Build It... Try It...Tell Us How It Sounds!!"

Hear, hear.

I think this is an interesting idea to prototype. The first board could be flexible enough to try several variations of the core idea.

Brian





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