The Phoenix is Audio-gd's best headphone amplifier. It features balanced input and output, a digital 70 or 99-step volume control system, heavy-duty aluminium chassis, current-domain amplification and is designed to work with as wide a variety of headphones as possible. It also works as a high-end pre-amp. The power supply and control circuits are housed separately, in the manner of the Mark Levinson No. 39 pre-amp, with the amplification circuits in their own dedicated box to ensure the best sound quality and least distortion and interference possible.