fixing hum on Rega Rp6

@mcanaday,

Did you try as I suggested unplugging the 24Vac TT power supply wall wart from the mains power outlet, turning/rotating it 180 degrees and then plugging back in?

Did you watch the video I provided in my second post?
https://www.youtube.com/watch?v=CAY2rRsqHLE
You would not have to disassemble the 24Vac PSU unit to add the ground wire. All you would need to do is loosen the two screws just enough so you could insert a bared insulated piece of 20 gauge wire that would be sandwiched between the cover plate and chassis of the unit when you tighten the two screws back down. You could even bend a hook on the end of the wire so it would hook around the screw.

Connect the other end of the wire to the ground lug/terminal on the phono preamp.
The ground wire will put the chassis of the 24Vac TT power supply on the same ground plane as the phono preamp chassis.

I think the hum is from the wall wort for the Rega PSU...

mcanaday

Your PSU may be reacting to something on the same circuit.
Get an extension cord and have it go to another room not on the same circuit as the one currently. Plug your PSU into the extension cord.
is the hum still there ? .

I did watch the video and that is my plan!  Thanks.  

Also - for now- the hum is gone.  I moved cords around so maybe I was just getting some interference...

But I think I’ll ground the PSU just to be sure.

Thanks for all your suggestions!