Micropower Headphone Amplifier

by Jerry Catanescu, March 2026

Here's the lowest idle current headphone amp I could come up with. It draws just 350 microamps. You will not find any dedicated headphone amp chip on the market sipping so little quiescent current.

There's nothing special about the schematic itself -- it's all about thinking outside the datasheet. The op amp I picked, although able to put out a very beefy 150mA, has no THD data for loads below 600 ohms, so it's probably off most people's radar for this kind of application (loads as low as 16 ohms).

If you want to build something based on this idea, just stick with the non-inverting configuration and unity or very low gain. Inverting doubles the THD, and any gain above unity also increases THD due to less negative feedback available. It can really use every bit of feedback to keep distortion low at such low quiescent current.