Classic Over-reaction!

So today I was listening to a new vintage LP that had just arrived. And when I switched cables from my phono stage to my Hegel 160 integrated - just to note sonic differences between cables -- I noticed that all of a sudden - for the first time - a noticeable hum was emanating from the Hegel’s transformer.

Crap. What now?

I switched back to the original cables. Nothing. The hum was still there.

I tried different tubes in the phono stage. Nothing. The hum was still there.

I unplugged the Hegel from the wall outlet and plugged it into the power strip. Nothing. The hum was still there. I switched everything off in despair and moped upstairs for dinner.

Where I noticed the toaster oven was on. Hmmm. A few minutes later the toaster oven dinged and turned off and I went downstairs, turned the Hegel on, and the hum was gone.

Sigh....