The Yamaha AST-A90M is a processing amplifier designed to work with the exclusive AST System speakers. It features a unique negative resistance circuit that eliminates voice coil impedance, allowing the amplifier output voltage to directly drive the speakers for powerful performance and steady damping power. The unit also utilizes an Air Woofer system where air in the port functions as a diaphragm to reduce distortion in the low range.
The AC OUTLETS can supply power to audio units with a power consumption of up to 100W.
The unit supports voltages of 110/120/220/240 V AC at frequencies of 50/60 Hz.
The manual specifies that batteries of size "AA" are included with the unit.