Apheared 47 (Apheared) is an individually hand-made portable pocket headphone amplifier, built to power and improve the potential of quality headphones. The amplifier was first introduced by (Benjamin Feist) to power the headphones of those who demand the highest quality of sound on the move. Designed to meet the exacting quality of relatively low impedance (32 Ohms) Grado headphones, the components are selected to meet the exacting quality of the most demanding music lover.

Each Apheared unit is constructed with high-quality well known parts, and is individually tested to make sure it is completely operational and produces high quality sound output. The circuit is based on ‘audiophile suggestions’ and ‘Texas Instrument/Burr-Brown AB-051’ application note, titled “Double the Output Current to a Load with the OPA2604 Audio Opamp”. Likewise [Apheared] has parallel ‘Op-Amp’ chips (dual OPA2227) and five resistors on each channel, economically driving a 2.8V peak signal into the 40 Ohm headphones.