This is probably the easiest way to wire up a Nu system! How much simpler can it be? This one is for a custom 4-string bowed electric bass, but can of course be applied to any instrument. The two stereo output jacks can connect directly to your (analog/digital) mixer or an audio interface. The Nu capsules are self contained active pickups. You use them just like any active pickup. Simply provide power (5v to 18v) and you are good to go!
Note: R=Ring, S=Sleeve and T=Tip
I suppose you can even passively mix the outputs to mono or stereo if you wish, by adding a 5k to 10k summing resistor to each output. For mono, simply tie all 4 outputs using 4 summing resistors, or better yet for stereo, tie 2 outputs to the left and the other two to the right, again using summing resistors. I think the stereo version can apply to 6 to 8 strings (2-4 inputs per channel). It may even be possible to have individual pots per input to give you better control. Take note that this scheme is only recommended for use with musical instrument amplifiers with high input impedance >100kΩ (e.g guitar amplifiers).
Here’s a passive mixing scheme for the stereo version:
Many thanks to Herald Labial, for the nice wiring diagram!