Visually like the smaller brother PM655, but here each channel has its own transformer and the output stage consists of 8 transistors, instead of 4 transistors as in the PM655.
The number of mesh cells and the structure of the precursors as well as other details are identical to the smaller PM655.
The PM665 was a multiple test winner in various trade magazines at that time.
Stereoplay : Top class 1, Audio top class
The original operating instructions for all harman/kardon devices are available on the hk website