Hum on Tube Amp - Can't find source


I have a hum (60hz) I can hear on my speakers and it happens with my tube monoblocks (either of them).  With or without interconnects, it even happens on either amp (have tried one at a time) with every circuit on the house tripped/disconnected, every other component disconnected from the wall (including the Internet/CaTV line) and no interconnects.  

One amp has it as soon as it warms up whereas the other one is intermittent.

Hum X doesn't solve it, iFi Ground defender either, AVA HumDinger on powerline  doesn't solve it either.

I have replaced the tubes and both amps were just tested at the factory.  Replaced the circuit breaker, tightened every wire on the breaker box, checked and cleaned all connections to ground rod.  Added a hum eliminator to the internet line.

Hum cycles a bit with the tube glow matching the cycles.

I'm waiting on the power company to come check the power coming to the house.

Thoughts?

ervikingo

If not, it's on your mains.  Get engineer in.

Without anything plugged in it is unlikely to be a ground loop.

@holmz    I didn't say it might be a ground loop, although it may be.

If OP reports correctly the hum is exactly 60Hz, the coincidence is too much.

That's why I suggested to test the rig in another location.

@wsrrsw i haven’t yet but I’m about to. 

high end not “audiophile” outlets. 
 

Just tried again tripping every panel and breaker except for the amp’s outlets. Comcast line disconnected outside the home BEFORE the ground block (this nothing from Comcast is connected to the house). Nothing else plugged in and no interconnects plugged in. Noise remains. Connected to my Aerial speakers, noise present. Tried both amps, problem on both 

Has to be an issue with my wiring, the power coming into the house, the ATS, whole house surge suppressor or got lucky and have two separate amps with the same malady(and what are the odds of that?)

only other thing left is the cellphone of the alarm system which has a ups. It is located 20/30’ from amps. I wonder.