Hello Dieter, thanks for the fast and informative reply! I suspected that
this was the case but thought there was no harm in asking. It is really a
fantastic module all the same.
Also, thank you for your work in standardizing the EuroRack format -- I am a
new manufacturer introducing modules for video synthesis and processing to
the EuroRack world and am very excited to see how things develop with this
new application.
Cheers,
Lars
On Tue, Mar 15, 2011 at 11:05 AM, <yahoo@doepfer.de> wrote:
>
>
> > Hi! My first post.
> >
> > Is it possible to modify the A-143-1 for linear response
> > envelopes? I have
> > purchased one as a modulation source in my video synthesis system, shown
> > here:
> > http://www.lzxindustries.net/introduction
> >
> > For video, the exponential response envelopes are not as useful as I
> would
> > like, but otherwise the module is fantastic for my purposes!
> >
> > Please let me know if there are any tips on doing this
> > modification, or if a
> > portion of the circuit schematic is available so I can attempt to
> > figure it
> > out.
> >
> > Thank you,
> > Lars Larsen
> > LZX Industries
>
> Sorry that's not possible with justifiable efforts. Standard envelope
> generators (like the A-140 or A-143-1/2) are based on a simple
> charge/discharge circuit where a capacitor is charged/discharged via a
> variable resistor (rotary potentiometer). This generates the well-known
> exponential response. To obtain a linear response a voltage controlled
> current sink/source would be necessary instead of the resistor. Such a
> circuit is much more complex than a simple potentiometer. It is used e.g.
> in
> the VCADSR A-141 which is much more expensive than the
> non-voltage-controlled version A-140.
>
> Best wishes
> Dieter Doepfer
>
>
>
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