The AIWA FX-90 is a high-end audio component that was introduced by the AIWA Corporation in the late 1980s. It is a stereo integrated amplifier, which means that it combines a preamplifier, power amplifier, and tuner in a single unit. The FX-90 was designed to deliver exceptional sound quality and was considered a pioneer in the use of digital signal processing (DSP) technology. It featured a high-performance digital-to-analog converter (DAC) and a 16-bit DSP chip that allowed for precise equalization, dynamic range control, and noise reduction.The amplifier section of the FX-90 utilized AIWA's proprietary Ultra Low Distortion (ULD) circuitry, which promised low distortion, high power output, and wide frequency response. The FX-90 also included a variety of inputs and outputs, including phono, tape, FM, and Aux.The FX-90 was visually distinctive as well, featuring a sleek, postmodern design that was popular in the late 1980s. It is still considered a highly sought-after collectible item among audio enthusiasts today.Overall, the AIWA FX-90 was a groundbreaking product that played a significant role in the development of high-end audio components during the late 1980s and continues to hold a respected place in the industry's history.