[sdiy] small VCO core

[jorgen.bergfors at idg.se]

>I originally did some LFOs this way, but of course I discovered that
>the glitch point in the sawtooth conversion basically made the waveform
>useless (unless you like that sort of thing!).

   On my VCO the glitch is only visible on the scope above 1 kHz.
   For an LFO, you could easily remove any hint of a glitch with a simple
low pass filter.

   /Jorgen