μSUM is the successor of KNEAD and has an improved circuitry and PCB layout. It was inspired by the famous MOOG CP3-Type Mixer. The circuit adds some nice harmonic distortion to the signal with heavy clipping, if the inputs are turned to the maximum. As the mix is bussed passively turning one input up may result in a reduction of the other inputs. Therefore the output cannot exceed any other input´s level providing auto-leveling on high volumes.