Sonic 6 VCOs

[tomg]

I've worked on these things off and on for 3 years. The problem is the
original design used a uA726. I don't have one to experiment with or
I think I would have been able to complete this sooner. 

I could always get it working but linearity was a major problem...
The damm thing would not scale......No matter what , I could only
get about an octave before it went flat. This is the last VCO I know
of that absolutly required a uA726.

You can play around with the expo if you like. I have tried everything
just so you know and this is the only sceme that I know of that will
work. The heater is not necassary. 1K tempcos will work just fine.
However pins 14,13,12 on the 3046 must be at gnd.

I replaced the uA726 with a LM3046 using one of the transistors for
a chip heater. Note the way the heater is hooked up, it looks backwards
but this is correct for this application. While I was at it I replaced the 4
fets with a 4066. It worked a lot better than I expected. Oh I added
sync too...just because.....:-)

Why spend 3 years working to get this going?....dunno?? Just stubborn
I guess. I have had an outstanding  multi-wave VCO for years now. For 
some reason I kept at it. It turns out....mostly because of my modifications...
that this is the cheapest multi-wave VCO I have ever seen. It is very
musical and stable....now anyway....

There are a couple of descrepancies between the schematic and layout.
You will have to add the init-freq trimmers to the layout...I left them 
off because I'm dead tired..... and stupid because my brain shut down 
sometime last night. I would have fixed  it but my mouseatosis is really 
kickin' after a week of parts lists and schematics....So just deal  with it. 
Ok? 

So...now all I need is to reverse enginner the uA914 and we can have a
S6 clone.....Anybody know whats in a uA914?

Schematic and DIY layout
http://www.xavax.com/efm/cbook/s6vco.html

Merry Christmas
Tom