They offer a number of modifications to the unit. As i�m a Meridian HD621 + 861 user the Oppo 93 will function as a transport only and thus I have opted for their Signature HDMI upgrade package. This includes a number of proprietary modifications to increase damping. It also includes the installation of a new cryo treated power supply as well as the installation of �Super Effect� AC Bybee Bullets on the AC rails between the IEC and inlet power supply. It also includes the installation of a new ultra clock (ultra low jitter) and swapping the internal wiring with Kimber Kable manufactured product. They also replace the stock IEC inlet with a Furutech product and upgrade all the electrolytic capacitors. RF absorbing techniques are also incorporated into key areas as well as a host of other modifications. No modifications or changes are done to the analog audio side (unless you request them to do the same).