>If you want to have a sweeping band-limited pulse-width modulation,
>then it's just to take 2 buzz's with different pitch,
>instead of using deltapi.. (And then subtract and integrate,
>as Josep M Comajuncosa suggested)


That's the technique I used in vco.  Modulate the pw parameter around .5.
(.5 is a square wave, 0 and 1 would be the limits of reasonable usage.

Hans Mikelson