KVT-915 DVD head unit is a normal unit. The XXV-05V is the 25th Anniversary edition which is a limited edtion only and it is design with more high quality component internally.Gold series caps,copperplated ground shield and improve signal to noise ratio
Everything is better in the XXV-05. It includes dual 24 bit BBE DAC, copper chassis, everything is gold plated for better signal transfer. If you jsut listened to them side by side, you'll immediately hear the difference.