Input Section in Stereo Summing Box ToolMix32
Analog Summing Gear ToolMix
The picture shows 3 of the 16 stereo inputs of a stereo summing box ToolMix32, each with pan-pot, rotary level control mit calibrated center detent, cut siwtch, PFL switch and 3-color peak-present LED indicator.
Stereo Summing Box ToolMix32 

ToolMix32 detailed View Input Section