Sorry Ernie what was I thinking? Mine is a Audio Technica AT-LP60. His is a U-Turn Orbit. I have tried with short cables. I have tried with alligator clip lead from the metal tone arm to RCA output ground. It lessened the hum but still not passable.
By the way, what's in between the cartridge and the seventy foot cable?
Built-in phono->line level preamp I suppose. They say internally grounded but there isn't very much metal in the whole thing
Great idea on the headphones buzz. Ed sorry I'm not sure what you mean by transformers.