Modules A-138p and A-138o are used to built a simple performance mixer (instead of an external stand-alone mixer). The module A-138p is the 4-fold input module while A-138o is the output module that can be combined with one or more A-138p's, resulting in a mixer with four, eight, twelve or even more inputs.
The A-138p Performance Mixer Input features four identical input channels. On top is the input socket with a peak LED, the input gain control for adapting to different signal levels is located at the bottom for practical reasons, just besides the mute switch.
Beneath the input there's a potentiometer setting the aux send level. Per channel you can determine whether the aux control is pre or post.
The next potentiometer sets the panorama position for the according channel and below we can find a bigger potentiometer responsible for the channel's output level which is then sent to the output module.
The A-138p input module can't work by itself. An A-138o output module is required to which you connect one or more A-138p's.
3U Eurorack module, 16HP wide, 40mm deep
no current draw