A Sansui 5900Z 75 watt/channel DC coupled receiver from 1980, with a digital synthesizer tuner. I'm checking it out and am very impressed. It sounds just like a G Series so far, which is saying plenty.
UPDATE: Wow. This is a refined and powerful receiver. I shouldn't be surprised...December 31st 1979 wasn't the drop dead day for superb, well made, reasonably priced gear.