The Burr-Brown/CMoy headphone amp designs are a harmonious blend of simplicity and elegance, offering audio purity with minimal components. These battery-powered amps provide a clean, hum-free listening experience, isolating the audio from power grid noise. Their DIY-friendly nature makes them a favorite among audiophiles, allowing for personalized tweaks and enhancements. Portable and historic, these amps carry a certain charm, reminiscent of a time when audio technology was simpler yet profoundly impactful. When discussing their technical aspects, the focus shifts to clarity and precision, ensuring the essence of their design is well-understood and appreciated. They are the haiku’s of the simple, headphone amplifier world.

I had to build one, and so, I built three. A friend did some testing for me, and I ultimately redesigned the veroboard layout three times to eliminate all kinds of EMI/Thermal noises etc. Version 2 was used at work, but was stolen somewhere during the ‘retrenchment’ phase. Version three is still with me, and a special beast. I can power it with the TBone supply, with not too much noise, but it is better powered by a 9V battery (and lasts a very long time).

My design below is hardly changed from the originals. I include the schematic and bill of materials for your convenience. Build this into a metal enclosure if you can. Aim to go as small as possible, for extra points.

(I used EAGLE back before Autodesk took away the free version).

This schematic includes power supply based on LM317LZ, which you can omit if you are going to power it your own way.