Fully balanced w/ zero feedback Codex pictured here is hand built in Boulder Colorado by Ayre Acoustics who helped design the digital cirtuitry in Neil Young's Pono player. Plugged in to it are the Audeze LCD4 reference headphones. The Codex works as a standalone DAC, headphone amp, or digital preamp, The quality of the sound is perfect for serious listeners, and looks stunning on any tabletop. Currently available for $1795. Price increases to $1995 starting April 1st.