This week, with a little help from a Roomba, [Dino] built a guitar pickup and preamp that ... and decouple the circuit from the input and power rails. He epoxied the piezo element inside the ...

Each of the four PowerWire cables comes with a built-in preamp ... any guitar active pickups, which are highly regarded for clean, clear and powerful sonic delivery. The integrated circuit is ...

The preamp circuit is pretty simple, being a two-stage single-ended design using both halves of the tube. Between the two is a three-band tone control circuit as used in classic guitar amplifiers ...