A-138a Linear Mixer

Doepfer's four channel mixer with linear controls, made for mixing control voltages: each input has its own attenuator, and a master attenuator sets the output, so the mixer can also end an audio chain.

Key features

• Four inputs, each with its own level control (In1 to In4)
• An output level control (Out), unusual on an A-100 module
• Linear potentiometers, for control voltages; the A-138b is the same mixer with logarithmic ones, for audio
• With nothing plugged into Input 1, In1 gives a DC offset of about 0 to +5 V (an internal jumper)
• In aluminium or as the black Vintage Edition