[Ed in Tx]

Originally Posted by maxhifi

Also, shure cartridges sometimes strap one negative terminal to chassis ground, meaning if it does not hum with the ground wire disconnected leave it disconnected. This isn't a safety ground, it's just for hum reduction

Not just Shure does that. Most all MM cartridges come with that strap to ground at one of the G terminals. If the tone arm head shell is metal or plastic with a ground to the cartridge body, that strap can sometimes cause a ground loop and hum. Remove that strap if using a metal or grounded head shell.