HK 630

The Harman Kardon HK 630, produced in 1973, is an audio receiver that features a distinctive design marked by a green dial face contrasting with a dark black top panel. It produces 30 watts per channel and was initially priced at $359.95. Its uniqueness lies in the separate power supplies for each channel, enhancing sound quality and ensuring cleaner audio reproduction. The receiver has a robust build and features gold anodized aluminum knobs. Instead of a traditional loudness switch, it is equipped with a 'contour' switch. The design incorporates twin power supplies for improved performance, allowing minimal cross-channel interference and maintaining high damping factor even at low frequencies, which aids in delivering clean bass. The 630 boasts a frequency response of 4-70 kHz with low total harmonic distortion (THD) at 0.5%. It can handle both channels driven simultaneously while delivering a power output that far exceeds similar units of its time. The dimensions are 17 inches in width, 13.75 inches in depth, and 4.75 inches in height, weighing 28 pounds. An optional wood cabinet was also available for aesthetic enhancement. While it is a highly appreciated model among vintage audio enthusiasts, it does have some common issues, including a problematic MPX IC that may need eventual replacement.