Noise Goblin

Ahhhh.  Well, turntable preamps are very high gain devices.  That is, they'll amplify the signal, and the noise, much more than others. You could be picking up EMF, but that usually needs to be closer, or picking up AC noise which the other components reject well enough.

Try a Furman power strip with SMP and linear filtering (they make lots of models without these features) which may clean up the noise enough for you.

How old is the hair dryer?  The old ones are  great source of the 'DC offset' problem. The would put a diode into the AC power line, that resulted in half-wave rather than sine wave power.

The audio circuit should be on the opposite leg in the box from any motors. Washer, fridge, garage door, hair dryer etc.

Have you checked the service panel? If audio is on the A leg, then the hair dryer circuit should be on the B leg. They should also have distance between them, ie, audio at top of panel, dryer at bottom.

OP, do you have another hair dryer, or something with a motor, you can plug in where the hair is plugged in. That will eliminate a funky hair dryer (though it may work great.)

I mean how often is that hair dryer on? Could it be just a noisy hair dryer, AND high gain on your TT, like Erik said.

Then for good measure move all the STUFF with motors, SMPS, goofy Christmas lights, cell phone charger, all the STUFF, to one rail in the main and your stereo on the other. Unplug the house and start plugging back in.

I’ve done it, a cell phone charger, and leds took me a while to figure out, but both made some noise that drove me crazy... I unplugged the hole house. The LEDs in my security system box were the problem.

I upgraded the SMPS charger to the cell phone and the CP to 4k or something like that. An installer for the security company, gave me the tip. ZERO floor noise. The second noise was a cable box PS, it took a ground loop device to kill the noise. I tried a few different ones. Just noisy.

EVERY other noise I’ve had, routing, takes care of it.. No cables touch each other, and there is at least 1/2 inch between them..Cross at 90s and still no touching...

Get yourself a new hair dryer for Christmas? :-)

Regards

Thanks all.  I will share this with my electrician.
To start I will be changing the gfi plug this week in th.e bathroom.