[sdiy] Phase-locked loops and the root of my headache

[Grant Richter]

> Not usually, but who knows what wierdness can be invented.

Here a good example of invented Wiardness, the #3 Standard Wogglebug

http://www.musicsynthesizer.com/WoggleBug/WoggleBug.html

> 
> mmmm, I think the answer is yes.  As long as the input signal's
> frequency is within the limits of the lock range, the PLL's VCO
> will follow it around like a puppy dog.

But the response is slew rate limited, i.e. permanent portamento. Also
damping of the step response is critical. The Wogglebug is a deliberately
badly built PLL with the underdamped step response used as a tone and CV
source.

It was inspired by a graph of vibrato intensity vs. time for string players.
Apparently, it is fairly typical to start with stronger vibrato on the
initial step and then decrease the vibrato amplitude over the note. The
Wogglebug is my attempt to build a circuit to do that function.

Have you always wanted to be a member of a "Secret Society"?

Now you can have a lifetime membership in "The Loyal Order of the Wogglebug"
for only $20. You have to provide your own Fez but the Order badge can be
viewed at

http://groups.yahoo.com/group/wiardgroup/files/wogglebadge.gif

and instructions for correct placement upon the Fez will be posted soon. Any
color Fez is OK, but for safety reasons, we recommend it not be over 27"
tall ;^)