Serge Waveshaper schemos on Music Machines

Scott Gravenhorst chordman at
Sun Jul 19 02:24:55 CEST 1998

On Sat, 18 Jul 1998 16:10:59 -0700, "Jim Johnson"
<jamos at> wrote:

>Don't want to offend anyone, but this actually looks like a pretty poor
>excuse for a waveshaper. All it does is derive an in-phase square wave and
>mix it in, correct? Not hard to do on any synth with two waveforms and a

It looks to me as if the phase of the rectangular wave produced by the
first opamp varies with P2, since the first opamp is a comparator
(according to the text).  This causes the period of the saw wave to
finally double as P2 is moved from 0 to max.  The problem with the
circuit is that it attenuates the signal from full to 1/2 output while
doing this.  That can be compensated for other ways, however.

I'd say that some interesting harmonics, perhaps similar to sync
should be available.  I'm interested enough to throw this one on a
solderless breadboard.  What the heck, it's simple enough.

-- Scott Gravenhorst
-- FatMan Site:

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