The signal distortion is small (0.1%), which is much better than general test power amplifiers.

This machine has protections from overload and short circuit. Even if the output terminal is short-circuited for a long time, it will not be damaged.

The output voltage can be adjusted by the knob on the panel and displayed intuitively.

Multiple units can be connected in series to form a power test bench with 8121C and 7116C. Power experiments can be performed on multiple speakers simultaneously, and their operation are easy.