My tube amp power supply is buzzing away Help

My tube amp - Mcalister Audio has an outboard power supply that buzzes quite loud. Not through the speakers, but the unit itself makes a buzzing noise I can hear 15 feet back - very obvious.

I have read there is some material you can buy to place under the transformer to help. The transformer does not seem well mounted - kind of lose. Can anyone tell me the name of the anti-vibration stuff and where to buy it. I think I am going to tweak it before calling the manu to replace.

Thanks,

Bill