Mixer logarithmic

Module A-138 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 - ie. it can be used to interface directly with an external mixer, amplifier, etc.
The module can be supplied in two versions:
A-138 a: potentiometers with linear response, so especially suitable for control voltage mixing.
A-138 b: potentiometers with logarithmic response, so especially suitable for audio signal mixing.

http://www.doepfer.de/a138.htm

• 10 mA +12V
• ? mA -12V
• 0 mA 5V
• 35 mm Depth

No info about availability.