Sansui AM/FM 4 channel music center integrated stereo receiver model MQ-2000. Has a built in turntable. From the early 1970s. Features, 2ch one tape in/output, one 2ch aux input, one 4ch front and rear aux inputs, synthesizer/decoder - 2ch - solo - concert hall - surround (decoder) aux 4ch, loudness on/off, noise filter on/off, tape monitor, cassette monitor, has a tuning meter, and separate bass and treble controls. These systems are rare.