The HDA100 is a rugged AC powered headphone amplifier that will provide excellent performance driving a wide range of typical stereo headphones. It will drive the usual 32 to 600 ohm high efficiency stereo headphones to teeth rattling levels around 120dB SPL with a combination of high output voltage swing (16Vp-p) for high impedance phones and a protected high current capability (0.2Ap-p) for low impedance phones. It will do the above at distortion levels below 0.10% and response flat to 0.25dB both measured over the full frequency range of 20Hz to 20kHz. The HDA100 is powered by 24VDC from an external power module such as the WA100-1. The DC power connector is center pin negative, sleeve position with a 2.1 mm center pin and a 5.5mm outer sleeve. Two HDA100 can share one WA100-1 with accessory DC loop-thru cable 20602-1.