The Technics SA-GX790 was my first "Pro-Logic" receiver. It was a true 120 watt/channel in Stereo and I believe 100 watt/ch X 4 in Pro Logic. That 2 X100 watts front, 1 x 100 watts Center, and 1 x 100 watts surround (50 watts/speaker X 2 wired together in series through receiver internals)...
I was looking back at my previous 1991 Kenwood KRV6030 documentation and found that the surround sound on this receiver was called Dolby Surround. The same name they call their up-mixing surround mode today.
However back in 1991 on the Kenwood, this was about the simplest surround system you...