This RX-V850 came out in the late 80's. It has no digital/optical jacks but it does have a phono in and monitor out along with a handful of other jacks. What I'm really interested in is the in/out connection with the jumper cables. I will be inserting a Behringer Equalizer to tweak the audio from this receiver.
As it is, it sounds excellent 'out of the box' without the eq. I'm using two Klipsch KF-28 towers on speaker A and two Klipsch RB-51's on speaker B.
The sound is rich and precise with great dynamic range and I don't need to go any higher than ten o clock on the motorized volume knob to feel the music all around... no surround needed!