How to shift voltage range from + to -?

[cs1729]

Hello,
I apologize if this is a terribly easy question or this is not the right place, but I am having trouble finding what I am looking for by searching google.

I have a Paia Midi2cv8 midi to cv converter that has a control voltage output for a pitch wheel. With no modification it outputs 5v and goes down to 0v when I move the wheel all the way down and up to 10v when I move it all the way up. This is an unusable range so I have a 10k pot to attenuate this range to something usable, however I would like to figure out how to shift this voltage so that it is 0v normally and -Max when I move it down and +Max when I move it up.

I want to do this so that I can find a circuit to sum the keyboard pitch cv with the pitch bend cv and if the pitch wheel is some positive voltage at center then I will be offsetting the keyboard pitch.

Thanks for your time.

 

[FvM]

An OP amplifier circuit can easily achieve this. See the Averager and summer circuits and Building a differential amplifier chapter of Lessons in Electric Circuits for the basic idea