Connect this Ultra Compact Phono Turntable Pre-Amplifier to your turntable and converts your phono signal to a line level signal - basically connects to turntable output to bring phono level up to line level. Load Impedance: 10K Ohms - Reference Voltage: 1V d State-of-the-art phono preamp to accommodate magnetic pickups. Ultra low-noise audio operational amplifiers offer outstanding sound and performance. Comes with 9 Volt battery compartment or a DC Power Supply for your convenience. Another Great Feature of the PP555 is that it has a 9 Volt battery compartment so if you don't need extra wires and another Power outlet, which makes this device portable and easy to transport. Voltage is 110V.