Wiardgroup

Hi Romeo
    I will do my best to answer your questions 'in line'...

--- In wiardgroup@yahoogroups.com, "vtl5c3 <rfahl@e...>" <rfahl@e...> 
> For mod 2 you've got the cathode of Vactrol VC1 connecting directly 
> to +15 V. 

correct! after this mod, Q1 drains current through ONLY VC1 and thus controls ONLY the 398's output.


> Looking at that and the 555 control circuitry in the third 
> mod,it looks like Vactrol VC2 is completely left out of the original 
> Wogglebug design.  Is that correct?

yes,
I eliminated VC2 from the design. I like the response curve of the more elaborate 555 control circuit and it freed up a Vactrol (a species that is expensive and in dwindling supply) for other evil plots.


> 
> The way I undersstand it, in the original design, the CV input based 
> around Q1 drives both vactrols in tandem, one which controls the 
> amount of the LF398s output going to the Smooth PLL, the other 
> controls the 555 clock's frequency.  
> 

quite right!'
I wanted the ability to control the two parameters you mention separately. As with all of my mods the changes were made to adapt the sound to my personal (and highly idiosyncratic (I'm told) tastes). But prompted by your questions, I should mention that these mods (1-3) DO CHANGE THE FUNCTION OF THE ORIGINAL DESIGN.

> BTW, thanks for submitting your mods... they look quite useful.
> 

and thank YOU for raising this issue as I probably should have addressed these points more explicitly in my notes

Perhaps I'm splitting hairs, but it would be possible to control both the 398-out and 555-rate with the same CV but the response curves would still differ from the original designs tandem vactrol arrangement




> Also, I've wondered what kind of craziness a sync circuit on the 555 
> would provide, such as the one on Rene Schmitz' VCO:
> 
> http://www.uni-bonn.de/~uzs159/vco3.html

precisely the kind of thought that keeps me awake at nights 
thanX!!!!

-doc