Dual Input Phono Pre-amplifier with Built-in RIAA Equalization The unit has both Phono and Aux inputs which can be independently switched to the line level output.This device allows a turntable to be connected to a Hi-Fi system which does not have a phono input. Dual Input Phono Pre-amplifier with Built-in RIAA Equalization, Power supply NOT included This device allows a turntable to be connected to a Hi-Fi system which does not have a phono input. It has RIAA equalization built-in, resulting in a perfectly balanced signal Power supply NOT included