I’ve come into possession of a Beogram 3000 type 5903 tangential tracking turntable quite unexpectedly…I came across it sitting in a pile of trash on the sidewalk in Manhattan. I took it home and hooked it up to my existing system using a 5-pin DIN to RCA adapter cable and everything seems to function well, but there is a pronounced hum. I’m assuming it is just a grounding issue. What would be the best and/or easiest way to establish a good ground connection to the grounding screw on my amp? I assume one of the DIN pins carries the ground wire?