Doepfer

--- In Doepfer_a100@yahoogroups.com, Florian Anwander 
<Florian.Anwander@c...> wrote:
> Hi Ingo
> 
> > the simplest example is stereo panning.
> > one channel opens with a positive voltage while the
> > opposite channel is closed by the same, but inverted
> > voltage.
> Sorry, but panning requires no negative voltages. The VCA should 
close 
> completely with +/- 0 Volt.


hello florian,

yes, you are right, i should have explained better what i meant,
so i give it another go:

it is not so easy to mirror a voltage going from 0 to +5 volts
in order to get another voltage going from +5 to 0 volts
at the exactly same time. ideally both voltages should be
at +2.5 volts at the same time, so they have to be linear.
the use of a lfo would be obvious for that application,
but lfo's usually have an ac output (a145 waves for example
go from +2.5 to -2.5 volts).

to obtain panning without a dedicated panning module
it is easiest to set the gain poti of two linear vca's
to 5 (half open) and then use a triangle wave from a lfo
on one vca and the same, but inverted triangle wave on the
other vca. there are other ways for sure, but imo this is
the easiest way, as long as you have the modules necessary.

best wishes

ingo