For a quick fix, take two "C" clamps, and clamp down each side of the steel plates that make up the 'iron' of the transformer.If you go clamping around on an E-I core transformer, be sure to add insulation (i.e. a plastic washer) under one side of the clamp! This will prevent the possibility of stumbling across a configuration whereby the clamp shorts out the magnetic circuit.
New Transformer possible?
I have a Beard 500 tube preamp,I believe it was made in early 80s,I really love the way it sounds,fantastic highs,mids are spot on bass is tight and tunefull.The problem is noise from the transformer,its just from the preamp,But it is loud enough to hear from my chair. I hear no noise of any kind from my speakers.I would like to know if a new transformer would take care of the noise/hum.I could always get a new preamp, but to find one that sounds as good as this one would be tough,or very expensive.Any help advise would be appreciated. Thanks MAXWELL