How to Build the CMoy Pocket Amplifier

Chu Moy designed a very popular headphone amplifier that’s easy to build, and it can be built small enough to fit in a pocket, power supply and all. It’s powerful enough to drive very inefficient headphones to thunderous volumes from even weak sources, and it sounds excellent considering that you can build a bare-bones CMoy amp for just US$20, and a pretty nice amp for under $50. Considering that the cheapest of the worthy commercial amps is $100 and most of them are in the $200+ range, this is a very worthwhile cost difference.

For 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.

If you are a raw newbie and don’t yet have any tools, see the companion article, Getting Started in Audio DIY.