Transformer hum

[John Garza (3665)]

Any suggestions on reducing transformer noise on older AC powered desk machines?

* Transformer is in excellent cosmetic shape - zero corrosion, dust, dirt.
* But it is 50 years old so aging adhesives/laminations
* Running at 110V mains vs. 120V reduces noise slightly (as per physics)
* Bolts appear to have vibration reducing washers - likely have failed. May try replacing
* Was initially silent, but using it more often over the past few days, the noise started.

-John