Doepfer A-138b Exponential Mixer - Standard

You are looking at the Doepfer Module A-138b Exponential Mixer.

The Module A-138b is a four channel mixer, which can be used with either control voltages or audio signals. Each of the four inputs has an attenuator, and there's a master attenuator, so that the mixer can be used at the end of the audio chain - i.e., it can be used to interface directly with an external mixer, amplifier, etc. The A-138b mixer uses potentiometers with logarithmic response, which are especially suited for audio signal mixing. Note: Since April 2004 improved versions of the modules are manufactured.

For the revised versions control In1 works as a DC offset generator (about 0...+5V) provided that no patch cord is plugged into socket In1.

If this feature is not required, it can be deactivated by removing a jumper on the pc board.