Hum aint fun

separate phono stage. Thorens td-124 with ortofon rmg-212 arm.

If you don't have a ground wire from the metal (if metal) turntable chassis, try one from it to the preamp phono ground.

Hifivn- thanks but i already tried this and it has not changed

If there are no wires under it, that's odd. No AC shielding through a wood arm mount though, if that is the case. Could the hum possibly be the mechanical vibration from the motor coming through the cartridge? Hard feet, or something else that made the suspension (springs/rubber?) stiff, will sometimes intensify a mechanical hum.