Headphone Output Power
Headphone output power states continuous electrical power per channel into a specified headphone load.
The load impedance must accompany the value, along with the output connection and stated measurement conditions. Milliwatts and watts are different units of the same quantity: 1,000 mW equals 1 W.
Headphone Output Power — Digital Audio Player
On a portable player, the figure describes the built-in headphone amplifier under the specified operating conditions. Different sockets or power modes can provide different limits, so their labels belong with the result.
Compare continuous per-channel figures at the same load and similar distortion and frequency conditions. A power figure measured at another impedance is not a direct substitute. Headphone sensitivity is also needed to relate electrical power to acoustic output; a larger power rating alone does not tell you how loud every headphone will play.
Headphone Output Power — Headphone Amp
On a headphone amplifier, this rating describes the power available at a particular headphone output into the stated test load. It is separate from a speaker-amplifier rating or a brief peak-output claim.
Compare the same load, output type and distortion limit, and preserve whether both channels were driven. Do not add left and right ratings into one per-channel value. The headphone’s impedance and sensitivity both matter for matching; the stated maximum power is not a fixed amount delivered at every volume setting.