Calyx Audio FemtiPrice: $1950 each

Website: www.calyxaudio.com

Tim said: The Calyx Femti does a whole lot right and very little wrong, and does it in a neat, tidy, power- and space-efficient package at a price within reach of many audiophiles. In the world of power amplifiers, less indeed seems to be becoming more.

Read the SoundStage! Hi-Fi review.

The gist: Class D continues its impressive evolution.