[sdiy] Rene's VC-LFO

[Scott Stites]

> Hiya kids.

Hiya, Uncle H =-D

> Just built Rene's design.  The "improved" buffers are greatly
> recommended.

Yes, indeed.  I built a module that contained one of these and a quadrature
function generator for a friend of mine a couple of years back.  I'm slated
to build one for myself whenever I get into a module building vs jes havin'
fun mood.

Yesterday I put together a 12 stage VTL5C3/2 phase shifter on the breadboard
(using the expo sink from Rene's VCO4069 to drive the Vactrols).  I did it
to experiment with some stereo ideas a friend and I have been discussing.
Anyhow, I'm going to eventually have three expo sinks to individually drive
three sets of four stages.  If I wasn't so lazy, I'd breadboard the
tri-phase and try the parallel phase shifter idea.

> Some additional thoughts...
>
> There are three 'left-over' 4069 inverters. If you tie those to the
> three LFO outputs, you get tri-phase square waves.  There are also
> three 'lef-over' 4093 NAND gates... you could use them to gate
> the square waves on/off... or you could combine those square waves
> for even more waveforms.
>
> I have not tried the 4093 trick yet. I suspect you will get three,
> negative
> going, non overlapping pulses.
>
> Think outside the box !!!

Sounds like some good ideas there.  IIRC,  Motohiko Takeda built a version
of the tri-phase that replaced the 4093 with some discrete parts, in case
anyone is building one in limited space.

Or, I suppose one could 'share' the IC's with another tri-phase on the same
board.  I've thought about having two of them in one module, BTW, for
playing with 'ensemble' control signals.  They wouldn't necessarily have to
drive B*D's =0).

Cheers,
Scott