AXT Systems

PA-5 30W Class-D Amplifier
PA-5 Top Side
PA-5 Bottom Side
The PA-5 is a general-purpose 30W class-D mono power amplifier that can be powered from a 12-24V single supply rail. It is very efficient and does not require a heatsink for normal operation. 
The input top the amplifier is a balanced line-level signal. The power supply I used was a simple 24V 30W SMPS which provided a small, lightweight and efficient amplifier system for small speakers.