How to Build the CMoy Pocket Amplifier - Tangentsoft Aug 18, 2016For these reasons, I think that the CMoy pocket amplifier is an ideal project to get started in audio DIY. This article is written for the beginner DIYer, though if you just want a guide to building this particular amp, you can skip to the parts or assembly sections. How to Hack a Headphone Jack - Circuit Basics Copper wire ground sheath wrapped around two insulated audio signal wires. Two separate insulated wires, each with its own signal wire and a ground wire inside. Separate insulated wires for the ground, right audio, and left audio inside a single cable. Usually red wires are the right audio channel and blue wires are the left audio channel.