Hi list, hi Dieter,
I had this idea about a module I would love to have, maybe it already
exists, let me know if it does.
So, when mixing and designing sounds, I find myself using more and
more Middle/Side matrix for working on stereo. I thought of a module
that would be simple, cheap, very narrow (it could probably fit in 4
HP) and would make a great tool for generating and processing stereo
field.

It would consist of 4 inputs and 4 outputs with basic arithmetic
operations on audio signal.
So first there's a Left(mono)and Right input, the Right input is
normalled to the Left input so that if you don't insert anything in
the Right input, you have the same signal than in the Left one (mono
sound).
Then there is a Middle and a Side output. The maths behind that is
M = L + R
S = L - R
Once you got those outputs, you can process the side and leave the
middle as it is, for example, add spring reverb on the side only or
put a triangle wave on the middle and the multiplied triangle wave on
the side to get a fat wide stereo sound.

Then you need a way to send the sound to a mixer or recorder that
works in the L R way. For this the M S to L R is intended !
So there's a M input and a S input, you stick your processed sound
into these and the module converts it back to L R and outputs a signal
that you can use with your mixer or recorder.

So it's very simple,
L (mono) and R inputs
M and S outputs
processing
M and S inputs
L and R outputs -> mixer/recorder
It could be done with a combination of existing modules (inverters and
VCAs or planned 138e) but that would be wide and expensive...

You can use it with a dual VCA if you want to place your sound in the
stereo field, this way you can choose the amount of sound you want in
the center and at the sides.

What do you think of it