This is the Sansui G-6700. It was produced from 1980-1982 and had a list price of $730.00. It was rated at 90 watts per channel into 8 ohms and had a total harmonic distortion of 0.025%.
The Sansui G-6700 weighs approximately 35 pounds. It has tone controls for Bass and Treble and Filters for both Subsonic and High. It also has a loudness control. It has outputs for two sets of speakers as well as headphones. For inputs it has Phono, Tape 1+2 and Aux.
Nearly all the Sansui G series receivers are very collectible. Even this mid range G-6700 sells for around $700-800.