Circuit that fits inside the Amphenol AC3F3MW (picture below) and forms a clone of the FetHead.

Installation

Installing the PCB into the AC3F3MW, henceforth referred to as the housing, is relatively simple if you have the right tools

Preparing the housing

Remove both screws from the housing. Pull out the the male plug as far as it goes and desolder the wires. Then pull out the female plug. Untwist the wires so they're straight. Remove the solid wire connecting to the ground tab on the male plug, as it will get in the way. Remove any excess solder from the terminals using a desoldering pump and/or solder wick.

Soldering the PCB

Place the male plug in a vice with pin 3 (the pins are marked on the front of the plastic) facing upwards. Place the PCB between the terminals and solder pin 3. Try to slide the plug with PCB into the housing to see if it's aligned, if not, adjust it and try again.

Then solder pins 1 and 2.

Slide the male plug with the wires back into the housing and solder the wires to the PCB (black to G, red to +, and white to -).

Final assembly

Push the male plug with PCB into the housing while pulling the the female plug out. Screw the male plug in place. Twist the female plug one or two revolutions to make the wires roll up a bit. Tuck the wires into the center and slide the female plug into the housing and screw it in place.