How to get rid of transformer hum?

Steve

The mfg said that is the power that is causing the hum and sure enough when I made the filter it got rid of about 80% of the hum. I posted this thinking that someone else might have a easy cure. I'll clip some more diodes across to see what happens since they cost about 60 cents a piece. Thanks again for your input.

Tommy, Sqjudge has the right idea. I had a Levinson 335 with the same problem, Madrigal technical guys here in London UK suggested the transformer (in my case 4KW) which works perfectly
Fchurtic

Lets see what we got so far. The mechanical hum couldn't been a design problem, for that would have surfaced and licked at the maker's QC dept.
I agree with Stevemj 5-14-01 post part about loose laminations or windings acting up. Varnish which is used to fill gaps in trans. or motor windings do deteriorate with time. Tommy, it might be worth your while to call a motor/transformer coilwinder workshop to check if all you need is a bake and re-varnish to seal off your misery! This problem is very common thing to electrical maintenance people. Get opinions of a couple of coil winders & their price to the job.
I've not had this same problem with my audio so far, but I have solved similar transfr hums (in my work) by tightening mounting screws or a re-bake/varnish at the winder's. I cannot guaranty this will work for you but a coat of insulating varnish does no harm, and I dont think is expensive. But try not start your conversation with the winder saying the usual hi-end audio stuff, you know what i mean :)

Tommy, have you tried to power these amps at another local? Away from your home? I saw that the mfg stated that its a power problem. I may not be an EE, but I have over 20 years in the field and 9 times out of 10 its not the equipment or the power but another source of noise on the line saturating the transformer causing it to hum. I know we all hate the power company and sometimes they are at fault. I'm just curious as to whether the problem follows the amps when they are powered somewhere else.

Here is the diode thing with a filter.
http://www.hifi-notes.com/ahacoffsetkiller1-en.htm