This useful module is a Bipolar Mixer, DC voltage source and Linear DC coupled VCA.
With no input to channel 1 the Input 1 pot becomes a voltage source with a range of +/- 6V. The control pot and input for channel 4 can be switched to become an offset control and/or a second CV input for the VCA.
Input 3 has 2x gain, so it can amplify lower level CV’s too.
All of the inputs are bipolar, which means that either non-inverted or inverted version of the input signal can be added to the mix depending upon the Input control being turned clockwise (non-inverting) or anti-clockwise (inverted). The 12’o’clock position is zero.