Aye. It's the lusted-after Sansui QRX-9001. Considered by many quadraphiles as the epitomy of quad receivers.
It has the Vari-Matrix circuitry that synthesizes a quad sound from stereo sources. Everything I play is routed through the decoder.
Admittedly the decoding is not equal to the Tate decoder and other very rare very expensive decoders but those other units are stand-alone decoders, not receivers.