[sdiy] VCO - sine output - why bother?

[Quincas Moreira]

Thanks all, what a great thread, I always learn so much from you guys :)

On Fri, Aug 26, 2016 at 12:26 PM, David G Dixon <dixon at mail.ubc.ca> wrote:

> To answer Quincas's question below:  It is relatively hard to make a sine
> wave directly without using a self-oscillating filter or a digital
> wavetable.  It is harder to get superior tracking in a filter than in a
> well-designed VCO.  Also, it is pretty hard to shape a sine into anything
> else, because it has no sharp edges or straight lines.  It is very
> straightforward to shape triangles or saws into the other waves with
> rectifiers and plus-minus amps, which are easy to design.
>
> Also, a sine shaper to get a sine with a THD of about 0.5 to 1.0% is
> convenient and cheap.
>
> I have another question about the sinewave issue (btw I love my sines, use
> them all the time, but only the filters in oscillation give me perfect
> sines)
> Is there not a way to make a sine core oscillator and derive the other
> waves from it? Like a filter with fixed high resonance for the sine, a
> comparator for the square etc...
> Why doesn't anybody do that?
>
> Quincas Moreira
>
>


-- 
Quincas Moreira
Test Pilot at VBrazil Modular
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20160826/9ca0c897/attachment.htm>