This isn't going to solve your issue, but as a side matter, a turntable should be placed on a dedicated shelf, tabletop, or rack space. Putting it on top of an amplifier is particularly problematic. First, because you don't want a heat source directly sitting below your turntable. Second, because you don't want to block or partially block the heat vents of the amp, which are usually there for good reason. I doubt there's any way you could get that turntable onto that amp and leave the vents clear.
Personally, I'd consider it rather risky from a safety standpoint to place anything on a top-vented amplifier, and most particularly on a 1970s-vintage amplifier.