[sdiy] VCS3 oscillators

[James Patchell]

You will need to be careful with the CA3096.  The PNP transistors are 
lateral PNP's and have very poor characteristics (very low Beta, for 
example).  You may not find that the circuit functions the same as it would 
with descrete parts.  One way to solve this would be to use the THAT340 
transistor array which has two PNP and two NPN transistors, and they are 
all vertical BJTs...very good performance.

But, the THAT340 is pricey.  (~$4).

At 11:25 AM 9/30/2004 +0200, Yves Usson wrote:
>Hello (2nd post)
>
>My questions are aimed at those among you who built a VCS3 or SynthiA clone
>or who are lucky enough to own one of these beasts.
>
>Does the shape control of osc2 and osc3 acts on the shape of the ramp
>signal or does it act only on the pulse shape ?
>
>What I understood from the schematic of the oscillator 1 (that can
>be found on internet) and from the reading of Jurgen Haible's messages
>posted some years ago on this list, the shape control of osc1 only
>changes the shape of the sine signal and not of the ramp signal.
>
>I want to build a clone of the VCS3 and I intend to use CA3046 and CA3096
>transistor arrays in order to reduce the number of parts and simplify the
>design of the PCB.
>Do you consider this would be a complete heresy or an acceptable compromise
>that would preserve the original sound ?
>
>Thanks for your comments.
>
>Yves
>
>Yves Usson
>email : yves.usson at imag.fr
>http://www-timc.imag.fr/Yves.Usson/personnel/SDIY

         -Jim
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