The Hitachi HMA-6500 is a stereo power amplifier launched in 1979, notable for its use of advanced power MOSFET technology. This amplifier features a robust design that incorporates only eight transistors per channel to deliver a significant 55W RMS output, with a remarkable total harmonic distortion rated at under 0.02%. This model is part of a broader range of amplifiers that Hitachi produced, which included the higher-powered HMA-7500 and flagship HMA-9500. The HMA-6500 is built with high-quality components, evidencing a sturdy chassis and carefully managed internal wiring to enhance reliability. It boasts an integrated circuit that disconnects speaker output during malfunction conditions as well as a dual coupling option (AC or DC) to suit various system configurations. The specifications indicate a wide frequency response from 5Hz to 100kHz, a signal-to-noise ratio of 115dB, and a damping factor of 50. Its dimensions and weight are approximately 435x153x306mm and 9.4kg, respectively, reflecting a solid build that prioritizes both aesthetic appeal and performance. Listening experiences with the HMA-6500 reveal a bold and energetic sound profile, making it suitable for a variety of music genres, while also presenting a somewhat clinical tonal character that may not appeal to all audiophiles. Despite its limitations in delivering warmth, it excels in dynamic range and low distortion, making it an interesting piece of audio history.
