There are no digital amps. The closest any come are the Zetex, Direct Digital Feedback Amplifiers, which can take PCM and convert it to PWM to directly control a MOSFET pair. But the amplification is still happening in an analog way.

Pioneer PDP-5020FD, Marantz SR6011
Axiom M5HP, VP160HP, QS8
Sony PS4, surround backs
-Chris