The Beyerdynamic A20 Headphone Preamp is a powerful stylish and extremely useful 2 channel headphone preamp which offers fantastic high fidelity audio reproduction in a compact and durable package. Featuring dual 1/4" Jack outputs at the front of the unit for connecting headphones RCA inputs/outputs transparent operation sound for an untainted tone and compatible with even 600 ohms headphones the Beyerdynamic A20 Headphone Preamp provides a professional 2 channel headphone pre-amp in a stylish and robust housing.