This is the Marantz PMS-3500. It seems to have been manufactured some time around 1981. Most of the Marantz boomboxes at that time have the same look. Some call it Marantz’s Gold Line because of the light silver and gold styling. The white dial face and meter faces add to the look.
The two speakers are detachable. As you can see it has one cassette and controls for Bass, Mid, Treble, Balance and Volume. It also features Level Meters for both right and left and adjustable muting level. There is also a nice little handle just below the cassette buttons that makes it easier to carry.