The Cycfi XR modern pickups use traditional techniques to pickup the vibrating string, but utilize a low impedance structure to create a full frequency response pickup with impedance matching output achieved using a low-noise preamp. This is essentially how active pickups work, like in EMG pickups. The worthy thing of note for Cycfi, however, is that it is all open-source:
Our projects are entirely Open Source. The designs (schematics, PCB layout, software, bill of materials, CAD drawings and source code) are freely shared, 100% free, under the Creative Commons Attribution-NonCommercial 4.0 International License. That means you can use the designs in your own projects for non-commercial purposes.
Very nice for the hobbyist and DIYer and unusual in the industry.
For multi-string pickups, the Cycfi Nu Capsule allows independent outputs per string. This is where it gets a bit more exciting in terms of opportunities for the modern guitarist. Traditionally this would be achieved using piezo pickup elements which have their own characteristic sound. Piezos also must be located at the bridge since they detect vibrations by mechanical pressure. The Nu Capsule uses a low-impedance coil and pre-amp all integrated in a small unit below each string. This allows flexible placement of the pickups rather than as a group as is traditionally done. Tailoring for multi-scale, 7,8, or higher string guitars becomes easier without using a custom pickup.
It’s good to see that the electronics world is also pushing the state-of-the-art for the modern guitarist.