The software would then add up the impedances just like an electrical engineer adding up impedances in an amplifier circuit.

FORBES: Magazine Article

He rummaged around in his bundle and pulled out a small, battery-operated Craig amplifier, then plugged a lead into an acoustic guitar that was broken in front and had pieces of wood rattling around inside it.

NEWYORKER: Romance

In the corner of his office sit two electric keyboards and an amplifier.

ECONOMIST: Frankfurt��s impatient maestro

The interesting distorted guitar on the track, an innovation in itself, was another piece of happenstance: somebody dropped the amplifier, or the rain leaked in on it, as the band drove from Clarksdale to Memphis.

ECONOMIST: Ike Turner

These electrostatic headphones with a vacuum tube amplifier, which came onto the market around 20 years ago, have become an icon in the audio world.

ENGADGET: Sennheiser unveils HDVA 600 analog headphone amp, asks for $1,600

The new luxury AH-NC600 earbud headphones offer music lovers an opportunity to enjoy the ultimate in private listening enjoyment, with a high-quality built-in amplifier and advanced noise-cancelling technologies that reduce outside ambient noise by 99%.

ENGADGET: Denon outs 2009 line of Blu-ray players, AV receivers and headphones