The Nu Multi is an active multichannel pickup utilizing one sensor per string. It is designed for independent processing with separate effects chains for each string, thus allowing different effects settings for distortion, EQ, compressor, delay, pan, pitch-shift, etc. Such extensive processing is now very possible due to advances in signal processing.
The Internal Breakout is the central hub that connects the Nu Multi pickup, monophonic pickups, and other controls to the outside world. The compact breakout board includes pins for 15 channels of combined audio and analog control voltages (CV) and switches (SW). Audio inputs can come from the Nu Multi pickup as well as other monophonic sources like standard active and passive guitar pickups. Control voltages and switches allow remote control of volume, tone, patch, or effects.
Follow link for more Info: https://www.cycfi.com/assets/Internal-Breakout.pdf
For older versions see: https://www.cycfi.com/assets/Meredith-1.pdf