thanks for the tips, itll give me something to get my teeth into :-)

Paul

On Wed, Feb 10, 2010 at 10:24 AM, < yahoo@... > wrote:

>
>
> > Thanks for the reply, yes i did look at the 132-3 but i simplt dont have
> the
> > rack space, i need to add 4 vcas. Changing the parts is no problem (i do
> > this all day at work) Are you able to let me know a parts list and which
> > need to be changed.
> >
> > Paul
>
> You do not simply have to change parts but to built a exponential current
> source which you can find in an electronic schoolbook (e.g. Tietze/Schenk
> Halbleiter Schaltungstechnik in Germany, but I'm sure there are many
> English
> books available too). Sorry - I don't have the time to write a detailed
> explanation how to do this as it's not that easy. In any case you have to
> be
> experienced with electronics. The exponential current source circuit is
> used
> in most of the CA3080 based filters and exponential VCAs and you will find
> it in the internet (e.g. http://www.musiksynthesizer.de/ p=84) . You may
> even
> use the exponential current source of the VCF in the Oberheim SEM module
> which can be found also in the internet.
> If you search e.g. for "exponential current source" or "exponential
> voltage-to-current converter" in Google or Wikipedia it should be no
> problem
> to find the circuit.
>
> Best wishes
> Dieter Doepfer
>
>
>


[Non-text portions of this message have been removed]