I agree with Stereofun. I can tell you, that from this engineers perspective, the Eight is the engineer's receiver. Sansui, in addition to everything else, made a groundbreaking statement with the amp section parameter adjustments. Most people have no idea, but there are some current values and adjustments typically done with 5% resistors (which means not even close) that hugely affect amplifier distortion, slew rate, and over all transparency of sound.
These parameters need to be adjusted to the equivalent of 0.1% on those same resistors. Sansui made those adjustments settable, with the 4 trimmers mentioned above. Now if they had just added a constant current source, it would have been the amp of the entire Golden Age of Stereo. Yamaha made such an amp with adjustable parameters and a constant current source in 1971, the CA1000. They went backwards after that.
None the less, it was a huge step forward. The most siginificant change, to me, in the 8D, was to go back to setting these parameters with 5% resistors. A real step backwards.
I imagine the problem was that technicians in the field could not figure out how to make the adjustments. The description in the Sansui Service Manual is worse than cryptic... you literally cannot make the adjustments from the description. I put a post up about how to do it some time ago. It is actually quite easy to do.
Just my 2 cents.