Hello ,
I had few of the rated recievers during this era 73-88 , models used were from Sony, Scott, Sansui, pioneer , Technics, Kenwood and lastly Onkyo. Sansui's always had good sound and looked good, but the real sleepers amongst them were the Technics and Onkyo.
The big Technics with power display IMO was the best sonically of the Jap recievers, good drive as the Sansui's , but without the darkness and i did go thru quite a few sansui amps , pre's and recievers during that era, the recievers were not as open as the seperates.
At the time the big technics was a match for my ML-9 power amp , talk about rude awakening ..