[sdiy] Radical New Module from Cyndustries!

[Ian Fritz]

At 05:56 PM 10/10/2003, Cynthia Webster wrote:
> >
> > The use of LFO frequencies that  increase with increasing drive frequency
> > is certainly novel and interesting.  But am I reading this right, there is
> > no way to turn this feature off?
>
>Well,
>
>If you present a negative voltage to the CV input, the animation will freeze
>at a fixed timbre which is an interesting feature.
>
>Simon says... FREEZE!

OK, but this freezes all the animation, right?  I was wondering if it was 
in any way possible to get the 4-LFO animation without the frequency 
tracking.  Might be a good mod for an adventurous DIYer!

>All kidding aside, we felt that previous designs had a flaw in that
>the LFOs are traditionally parked at arguably arbitrary frequencies

I don't understand how you can argue this.  The original writeup explained 
exactly how the frequencies were chosen.  They are in the ratio of 2.1^.2 
in order to avoid formation of repetitive patterns.  Whether this is a 
serious problem in practice may be debatable.

>and suffer from a phenomenon where some notes sound fattened more than
>others.  We feel that no other design has solved this as concisely.

Plus, you have added voltage control, a very important advance.

It isn't totally clear what the Fat control does.  It increases the 
frequencies of the LFOs, but does it also change the depth of the phase 
shifts?  And what happens when the FAT control is shut down and the CV FAT 
input is used?  (What, exactly, determines the four phase shifts?)  Sorry 
if this is too many snoopy questions.  Obviously you could have good reason 
to keep all this proprietary.

>There are always more features one can pile onto a module, but I felt
>that this was as you suggest a good balance of size and function.

Yes it is.  It's still interesting to debate different ways to do the 
trade-offs.

>Maybe I totally blew it by not adding the triangle output?
>I dunno, this combination just seemed to feel right to me, that's all

And that's all the justification that is needed!

Myself, I like the triangles, or a combination of some tri and some 
saw.  This does add a fair amount of circuitry.

>Scott Bernardi has another really excellent design as well!

Yes he does!

>Thanks for your comments Ian!

Thanks for the discussion!

   Ian