This small but surprisingly powerful amplifier is ideal when you want to connect speaker to a MP3-player or other devices with a headphone output. The power stage can drive large speakers as well, this will enable you to enjoy the full sound quality. There stereo input is internally combined, so you'll have both channels at the mono output. A 9 Volt battery is used to supply the amplifier. This kit contains SMD-parts, the battery is not included. Specifications: Output power 1 Watt Output impedance 4 - 8 Ohm Input impedance : 2 * 75 Ohm Operating Voltage 9 Volt DC PCB size : aprox. 31 * 38 mm² This amplifier is also available as an assembled module !