I have not read all of the replies to this, but I do have two solid
answers on circuits you can make quite easily yourself whiuch
will do what you need.

There is a CV scaler circuit on Chris McDonald's DIY page that
will do invertions. i have built a few of these, they work like a
charm.

Go here:

http://www.evenfall.com/diy/cvscaler.html

There is an even simpler method, which I will try my best to
describe here in text:

Get an op amp. Connect the power (both - and + - do not us a
single supply comparator). Make an input t (in which you would
connect your CV) and run it through a 10K 1% resistor. Take the
output of that resistor and route it to the ' - ' (inverting) input of
the op amp.

Now, run a standard feedbackloop from the output of the op
amp also to the - input of the op amp through a resistor. this
feedback should be another 10K 1% resistor as well.

Run another wire directly off the input and connect it to one side
of a 10K pot

Connect the other side of the pot to ground.

Connect the wiper of the pot into the + (non-inverting) input of the
op amp.

To match the Doepfer impedance, you should run the output of
the op amp also through a 1k resistor.

The output side of that 1K will give you a voltage which can be
scaled either negatively or positively depending on the setting of
the pot.

This will allow you to process an input as Buchla did it - you can
adjust the level (amplitude) of an incoming CV either
non-inverted ot inverted, with the ecenter point of the pot being
null (fully attenuated).

I have another circuit which will yield a positively biased
inversion, but I don't think this is what you are asking for. In this
instance, +5 would become ground and ground would become
+5.

So there you go,

Peter Grenader

--- In Doepfer_a100@y..., "mdimmm" <mdimmm@y...> wrote:
>
> Are there any other modules besides the A-175 that do voltage
> inversion of CV (A-119, A-116, A-136 ). The A-119 doesn't
> seem to handle CV signals very well, seems more suitable for
> inverting audio signals.
> Since I don't have any space left in my rack, is there an easy
way
> to construct a little outboard CV inverter
> Would the polarity switchers cable manufacturers sell work
>
> Thanks a ton.
>
> M. Dimm