No matter how many A-138p Input modules are connected, the A-138o Performance Mixer Output adds all of them to one stereo sum which is emitted at separate sockets for left and right.
Besides this all signals from the channel auxiliaries are summed, available at the Aux Send socket. The Aux Send level can be adjusted.
the effect signal has to return into the mixer somewhere of course, which is handled via the Aux Return mono socket. The Aux Return level is adjustable with a potentiometer.
Aux send, Aux return, left output, right output
3U Eurorack module, 4HP wide, 40mm deep
current draw: 20mA at +12V and 12V at -12V