[sdiy] Smith's Evolver Desktop's spikey VCO waveforms

[gordonjcp at gjcp.net]

On Wed, Jun 05, 2013 at 11:53:20PM +0200, Michael Zacherl wrote:
> Hi, 
> a friend's Evolver Desktop has a peculiar glitch in its VCO's waves.
> First, from his description, I suspected a trim pot being not adjusted properly but now he sent me some pics of the screen of his oscilloscope, and I can't tell what it is. [1]
> Of course it's audible.

That looks pretty normal.  Real VCOs don't have precise waveforms like you see drawn in books.  That's why they don't sound like the perfect-but-boring waveforms from high-quality digital oscillators.

VCOs suck.  That's why they're interesting.

-- 
Gordonjcp MM0YEQ