Most stereo amplifiers will offer digital connections such as optical, coaxial and USB, though fewer include HDMI ARC ports for hooking up your TV. HDMI is much more common on surround sound-savvy AV receivers.
However, some people like to use their stereo system to make their television sound better, and including HDMI is a neat way of making that happen. Cambridge Audio has recognised that with its Edge A integrated by including an HDMI ARC socket. Other examples with HDMI ARC include the NAD C 389, Audiolab 7000A and the more home cinema-aligned Marantz Stereo 70.