[Jamie]

Morzh,
Thank you so much for that information. That link you provided is like the answer from above! ... I can quote two sentences that mirror my experience perfectly -

"A comparable effect could be obtained, in a less elegant way and by introducing an additional component, by increasing the value of C1 from 4uF to 33uF in order to substantially reduce the ripple current across the field coil."

..and, this is exactly what happened to me,.,...

"...but no hum had been observed during the restore procedure, it appeared only after inserting the chassis in its cabinet."


Thanks!!!