vco8 (Axxe VCO)

[tomg]

Hey Juergen, are you still looking for that simple yet stable vco
for the 32 oscillator poly? I may have stumbled over something
you want.....It's the vco from the Arp Axxe. It's not quite as simple
as the unijunction vco1 as a matter of fact it's about twice as 
complicated as the vco1 but it uses common fets.

Why another vco? Well....Why not?...;-) No seriously..I have this
vision of a super simple all transistor synth. This vco completes
my shopping list. I have some really cool all x-istor stuff for this
thing.  It looks like the vco would cost (excluding pots/jacks/tc) 
in the $2.50 range. It seems very stable even without a tempco.
Anyway...on my road to the all x-istor synth I thought I might try
this for the vcos. I think we have a winner. I remembered JH
wanting a good little vco too so here it is.

Hey Harry, would you put this in EWB for us. I would like to know 
what you think and Juergen I know you like things in original form.
I'll give you a list of modifications if you want. All I really did was
change a few resistor values. It runs from +/-12 and +/-15 nicely.
I haven't tried it yet but I'm sure sync can be added by strapping
another fet across the switch the same way it's done in the vco4.

http://www.xavax.com/efm/synth/cbook/pics/vco8a.gif

-tg