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 :)
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 :)