The Yamaha AST-A10 is an Active Servo Processing Amplifier designed to work with specific Yamaha Active Servo Processing Speakers. It utilizes a unique technology where the amplifier directly controls the speaker operation, providing improved driving and damping force compared to conventional systems. The unit features interchangeable cartridges: one for optimizing performance with matching speakers (e.g., AST-KS1) and another ('flat amp' cartridge AST-KO1) for use as a standard power amplifier.
You must insert the Active Servo Processing Cartridge that came with the speakers.
Install the AST-KO1 "flat amp" cartridge included with the unit.
Turn the control knob under the front panel door counterclockwise.