Analogue question


As everyone else in the world this lockdown has been a change in "normal " behavior but has given many of us audiophiles plenty of time to listen to "our music " . Since I am planning to downsize my living space I have been going through various pieces of equipment to determine what I will keep and what I would let go . 5 days ago I have come across a maddening problem with my analogue set-up ! Everything sounds great until I want to play a record and before I even place the needle in the grove I get a serious hum through my speakers ! I originally suspected I was getting acoustic feedback because my amp was close to the speakers . Yesterday I moved all the equipment to a distance of 6-10 feet from the speakers and still get the hum when I switch to analogue. Starting to wonder if it is coming from the turntable itself but before I take the time and energy to reset a new rig thought I would post a question on this forum. Any help would be greatly appreciated . Set-up is as follows : Dual Golden turntable w/ortofon red cartridge , McCormack UDP player , Forte 2a preamp feeding Forte 4A amp , speakers are Vandersteen 1C , interconnects KimberKable Heroes ,speaker wire Nordost Blue and Tice power conditioner . 
wazoo
Was there ever a time when it didn't hum like this? What is different now?
When it is disconnected appears to be lower noise level but when I start playing a record it is the same when ground connected . No problems before only difference is I use a different outlet since the furniture was rearranged . Are you thinking the a/c line causes this even with the line conditioner ?
I would consider there may be an issue with the tonearm wires.  Recently had the same issue and had to address the wires in the base of my tonearm.  In my case the din plug required its set screw to be tightened as there was motion of the wires as the tonearm was moved since as the DIN plug was loose allowing a ground issue. This was a recently shipped tonearm but something similar could be occurring even with a continuous tonearm/TT cable