Yamaha AST-A 10	Comments
	Natural Sound Active Servo Processing Amplifier with two signal processing cartridges Manual available 2.12 mb PDF or hardcopy

The Active Servo technology Speaker system is an entirely new concept in hi-fi audio loudspeakers comprising the AST-A10 Active Servo Processing Amplifier.

The Active Servo Processing Amplifier has a high performance power amplifier built in. But it does far more than simply supply an amplified signal to drive the speakers: it actually controls the operation of the speakers directly, providing a dramatic improvement in driving and damping force over conventional systems.

Bass Range and Input Level controls are included to suppress excessively low bass response and adjust the input from a control amplifier (or integrated amplifier), respectively.
The rated output is unmeasurable, but at 6 ohms can be said to be equivalent to 70 watts/channel, and it has a dynamic power rating of about 100 watts/channel.