Harman/Kardon HK 770

Power output: 65 watts per channel into 8Ω (stereo)

Frequency response: 20Hz to 20kHz

Damping factor: 50

Input sensitivity: 1.2V

Signal to noise ratio: 123dB

Dimensions: 385 x 72.5 x 320mm

Twin Toroidal Power Supply

Weight: 10.1kg

Year: 1980

Harman/Kardon 700s : super-high bandwidth, swift slew-rates, discrete components only, DC design and minimal use of NFB.
More of the same since the early 1970s at H/K but, this time... different. For two reasons.


As sternly touted by Dr Matti Otala himself in Japan over dozens of ads and articles, T.I.M. and I.I.M. were the real enemies and nothing else.
T.I.M. stands for Transient Intermodulation Distortion, a nasty one that stems out of excessive use of negative feedback and results from increased I.I.M. (Interface Intermodulation Distortion) - all from the excessive use of NFB to reduce said distortion !

According to H/K, TIM is ten times more audible than THD and can be detected at leveles as low as 0,03% - read the TECH 1 explanation for the details about all those nasty distortions few ever... suspected :)

The 700s weren't made in the USA, just like said Citation series. They were made by the Shin Shirasuna Corporation, a company also known for products bearing the SILVER name.

The hk770 was an M770 in Japan and a Silver SA5050.