The Doepfer A-138M Eurorack 4x4 Matrix Mixer Module is a powerful matrix mixer module featuring 4 inputs and 4 switchable outputs that can be either individually unipolar or bipolar.

The A-138m is a 4 x 4 matrix mixer with switches for unipolar/bipolar mode for each column. Unipolar means that the controls work as attenuators. Bipolar means that the controls work as polarizers. In this mode the amplification is zero in the middle position of the corresponding control. Turning the knob counter clockwise from the centre position means the signal is subtracted from the output sum with increasing amount (i.e. negative). Turning the knob clockwise from the centre position means the signal is added to the output sum with increasing amount. The module is DC-coupled and can be used for both audio and control voltage mixing.

The main features of the Doepfer A-138M Eurorack 4x4 Matrix Mixer Module include:

• Eurorack Matrix Mixer Module
• 4 inputs
• 4 Outputs
• Individually Switchable Unipolar or bipolar Outputs
• Dimensions: 101.3 x 20mm