[sdiy] saw/ramp from square?

[Aaron Lanterman]

On Dec 31, 2008, at 4:26 PM, Scott Nordlund wrote:

> A simpler way to get a "sort of" saw would be to highpass filter the  
> square wave and then half-wave rectify the output.  It will have a  
> strange formant (and will similarly impart this formant when used  
> for PWM), but it's still good for some purposes. You could also  
> alter the wave shape by adjusting the highpass filter or DC offset  
> on the rectifier.

The Music Easel has a curious waveshaping circuit that does something  
like this to generate the "pulse" from the "square" (see lower left  
corner of Board 8 of the 208 Magnus's Buchla Page).

- Aaron