The pre-amp section employs a 6922 tube with a Class A output stage. This maintains a high level of detail while taming harsh compressed digital music. We couple that with an A/B amplifier in the final stage to achieve a very analog sounding product. The Nova has a USB input for your computer in addition to 2 coax, and 2 optical inputs for other digital sources like Squeezebox, Apple TV, Wadia iTransport, Airport, Sonos, and XM or Sirius tuners. It also has 3 analog inputs for docking stations, CD players, tape decks or phono preamps. If you want to add a subwoofer or outboard amplifier, the Nova features a “Class A” variable preamp-output and a fixed line output. Nova covers all the bases like no other product before it.