1/X circuit

[jhaible]

> And I've just noticed Paul's MOTM LFO does have a shape control. Any
> hints Paul? Or does your work in a different way.

I think I should answer this one.

It works like the VCS-3 shape control, not like the MS-20 shape control.
While at first glance, the MS-20 waveshape might look more attractive, the
VCS-3 waveshape is *way* more useful musically. (You can easily emulate
the MS-20 style non-symmetric triangle with an LFO-triggered ADSR,
but the VCS-3 and MOTM non-symmetrical ramp is hard to emulate with
anything else.)
While the MOTM LFO emulates the *behaviour* of the VCS-3 waveforms,
it's not a clone of the original circuit, but a completely new development.
The behaviour of the ramp wave is like this:

0%:
rising saw with very steep falling slope (unlike the MS-20 where even the
"fast" slope is rather slow)

50%:
Unipolar, symmetrical triangle

100%:
falling saw with very steep rising slope

in-between these extremes:
Complex waveforms that are partially smooth and partially stepped.

JH.