"A perfect partner for the SA14 and PM14 range or higher" The Reference NA8005 is an upgraded version by Fidelity Audio. The Reference upgrade significantly improves on the NA8005 sound quality. Treble is more delicate and airy, midrange opens up into the room offering a more 3D presentation. Bass extends deeper along with improved timing and dynamics. High Resolution and Quality recordings spring to life, the subtle changes in the audio are easily heard, complex audio is delt with allowing the listener to relax into the music.