[sdiy] 1v/oct expo converter front end for SSM2164 quad pole vcf..

[Jean-Pierre Desrochers]

I had not seen the expo voltage to current response
embedded for all the CV pins stated in the datasheet..
I'll have a look again in the specs.
Thanks David !
JP

 On Fri 30/03/12 12:54 , David G Dixon dixon at mail.ubc.ca sent:
> > Does anybody have a schematic for a
> > 1v/oct expo converter front end in a SSM2164
> based quad pole > low pass vcf ?
> > Some circuits around but they seem to be with
> linear front end summer.> I'd need 1v/oct for the VCF span.
> > I found this:
> > http://userdisk.webry.biglobe.ne.jp/000/024/65/N000/000/000/12> 5151002153016326829_Exp_SSM0908.PNG
> > But the front summer uses half of the SSM2164 as
> an expo converter..> The best would be to use the SSM only for the
> quad low pass > part of the VCF..
> > Thanks
> > JP
> 
> I have an entire circuit schematic I can send.  This is the basis of
> theIntellijel Dr. Octature filter in eurorack.
> 
> The 2164 has an exponential voltage-to-current response already, so all
> youneed to do is send the CV summer output directly to the 2164 VC pins (all
> ofthem tied together).  In other words, no expo converter is required for
> VCFswith 2164s.  The proper CV gain for 1V/oct is about 20% (or slightly
> less).You can expect about 5 octaves of tracking in this case.
> 
> 
> 
>