[sdiy] popping a cap into a VCO

[Oakley Sound]

 > Switching in a larger cap would do it.

Not always true in a sawtooth core. The discharge switch, usually a FET, 
needs to be active long enough to discharge the cap. That is, the 
waveshape would become degraded as the sawtooth fails to flyback 
properly. You may need to increase the reset time to allow this to 
happen. This would, of course, create problems with high frequency 
tracking as reset time should really be an insignificant part of the 
period of oscillation.

You can certainly try it, but watch with a scope to make sure the 
waveform does get reset properly.

Another way to increase the ability for the FET to discharge the cap is 
to put two FETs in parallel. This may require changes to driver circuit 
that drives the gate of the FET.

With a triangle core, you could probably assume that increasing cap size 
will have no detrimental effect on waveshape.

Tony

www.oakleysound.com